Hair & Nails

The head louse (Pediculus humanus capitis) is a blood-sucking arthropod of the suborder Anoplura. Lice are obligate human parasites that have infested humans since antiquity. Pediculosis capitis is an infestation of the scalp by head lice. It is estimated that 6 to 12 million individuals in the United States are affected with head lice per year.¹ Resistance to topical chemical pediculicides is widespread, and new agents have been developed to address this gap in care.

Characteristics of Head Lice

The head louse is a tan-gray–colored, wingless insect measuring approximately 2- to 3-mm long with 3 body segments. It has 6 legs with claws used to grasp individual hairs, and it moves by crawling; it does not fly or jump.^2,3 The head louse has an elongated abdomen and a small head with short antennae and anterior piercing mouthparts (Figure 1).⁴ Nits are transparent, flask-shaped, 0.5- to 0.8-mm egg cases found firmly cemented to the hair shafts approximately 1 to 4 mm above the level of the scalp (Figure 2).⁵ The head louse resides on scalp hair and feeds off the scalp itself. Both lice and nits can be present throughout the scalp but are most commonly found in the postauricular and occipital scalp.^3,4

Female lice live approximately 30 days and lay 5 to 10 eggs per day. Eggs incubate individually in nits laid close to the scalp for 8 to 10 days before hatching.^1,6 The newly hatched nymphs (also called instars) have multiple exoskeletons that are shed as they grow.⁷ Nymphs mature into adults in approximately 2 weeks, and the life cycle begins again.⁸ Head lice are obligate human parasites, feeding approximately every 4 to 6 hours on the blood of the host; however, they can survive up to 4 days without a blood meal on fomites if the climate and conditions are favorable.^5,9

Epidemiology and Transmission

Head lice infestations commonly occur in children aged 3 to 11 years and are more prevalent in girls and women.^1,10 Infestation rates are not reliably recorded, and few population-based studies have been performed; however, it is estimated that 6 to 12 million individuals are infested annually in the United States.¹ Prevalence in some European populations has been estimated to range from 1% to 20%.¹¹ A 2008 literature review found that worldwide prevalence varied across populations from 0.7% to 59%.¹⁰

Transmission occurs most frequently from direct head-to-head contact. One study found that transmission is most likely to occur when hairs are arranged in a parallel alignment and move slowly in relation to one another.¹² Although controversial and probably less notable, transmission also may occur indirectly via fomites or the sharing of hairbrushes, hats, or other headgear.^13,14 Classrooms are a common place for transmission.¹ A 2009 study in Germany found an increase in health department consultations for head lice when schools reopened after vacations. The investigators also found that pediculicide sales peaked from mid-September through October, subsequent to schools reopening after the summer holiday.¹⁵ There is some evidence that overcrowded housing also can lead to increased incidence and transmission.^16,17 There is no consistent correlation of infestation with socioeconomic status.^1,17,18

Clinical Manifestations and Diagnosis

Clinically, patients with head lice present with scalp pruritus and sometimes posterior cervical or occipital lymphadenopathy. Pediculosis also can be asymptomatic. With the first exposure, symptoms may not develop for up to 4 to 6 weeks as the immune system develops sensitivity to the louse saliva.⁶ Bite reactions consisting of papules or wheals are related to immune sensitization.⁵ Louse feces and excoriations from scratching to relieve itch also may be present on examination. Secondary infection of excoriations also is possible.¹

Diagnosis of an active infestation is made by identifying living lice. Because lice move quickly and can be difficult to detect, tightly attached nits on the hair shaft within 4 mm of the scalp are at least indicative of a historic infestation and can be suggestive of active infestation.^1,19 Dermoscopy is a helpful tool in differentiating eggs containing nymphs from the empty cases of hatched lice and also from amorphous pseudonits (hair casts)(Figure 3).^19,20 Wet combing improves the accuracy of diagnosing an active infection.²¹

Treatment

Effective treatment of head lice requires eradication of all living lice as well as louse eggs. Topically applied pyrethroids, including pyrethrin shampoos and mousses and permethrin lotion 1%, are considered the first-line therapy.⁸ Pyrethroids are over-the-counter treatments that act by interfering with sodium transport in the louse, causing depolarization of the neuromembranes and respiratory paralysis.²² Pyrethrins are natural compounds derived from the chrysanthemum plant; permethrin is a synthetic compound. Pyrethrins often are combined with piperonyl butoxide, an insecticide synergist that improves efficacy by inhibiting pyrethrin catabolism.²³ Resistance to pyrethroids has become an increasingly important problem in the United States and worldwide.

Malathion lotion 0.5% is another therapeutic option for head lice. Malathion is a prescription organophosphate cholinesterase inhibitor that also causes respiratory paralysis of the louse and is one of the few treatments that is ovicidal.²² It was withdrawn from the market in 1995 due to its flammability and a theoretical risk of respiratory depression if ingested; however, it was reintroduced in 1999 and remains an effective treatment option with little resistance in the United States.²⁴

Lindane 1% (shampoo and lotion), an organochloride compound that acts by causing neuronal hyperstimulation and eventual paralysis of lice, is no longer recommended due to its serious side effects, including central nervous system toxicity and increased risk of seizure.^8,24

New US Food and Drug Administration–Approved Therapies
Newer topical treatments include benzyl alcohol lotion 5%, spinosad topical suspension 0.9%, ivermectin lotion 0.5%, and dimethicone-based products. Benzyl alcohol was approved by the US Food and Drug Administration (FDA) in 2009 and is available in the United States by prescription.²⁵ Benzyl alcohol kills lice by asphyxiation. Phase 2 and 3 clinical trials showed significant treatment success 1 day posttreatment (fewer live lice than the vehicle alone; P=.004) and 2 weeks posttreatment (absence of live lice compared to the vehicle alone; P=.001).²⁶

Spinosad was approved by the FDA in 2011 and is available in the United States by prescription.²⁵ It contains the compounds spinosyn A and spinosyn D, which are naturally derived through fermentation by the soil bacterium Saccharopolyspora spinosa. It also contains benzyl alcohol. Spinosad paralyzes lice by disrupting neuronal activity and is at least partially ovicidal.²⁷ Phase 3 clinical trials published in 2009 showed that spinosad was significantly more effective than permethrin in eradicating head lice (P<.001).²⁸

Topical ivermectin was approved by the FDA in 2012 for prescription use.²⁵ It acts on chloride ion channels, causing hyperpolarization of the muscle cells of lice and resulting in paralysis and death. Oral ivermectin (200 μg/kg) given once and repeated in 10 days is not FDA approved for the treatment of head lice but has shown some effectiveness and is sometimes used.⁸ A comparison study of topical versus oral ivermectin published in 2014 found that eradication was achieved in 88% (n=27) of topical ivermectin users after 1 treatment and 100% (n=31) after 2 treatments. Oral ivermectin produced cure rates of 45% (n=14) after 1 treatment and 97% (n=30) after 2 treatments. Both topical and oral ivermectin treatments are well tolerated.²⁹

Physically Acting Preparations
Products with a physical mode of action are a new attractive option for treatment of pediculosis because the development of resistance is less likely. Studies of silicone-based fluids that physically occlude the respiratory system of the louse, such as dimethicone liquid gel 4%, have shown superiority over treatment with pyrethroids.^30,31 Although the safety of dimethicone has been demonstrated, silicone-based treatments have not yet been widely adopted in the United States and are not currently used as a first-line treatment.³² However, use of such physically acting pediculicides may in time surpass traditional neurotoxic treatments due to their low susceptibility to resistance and good safety profile.^33,34

Alternative Therapies
Nonchemical treatments for head lice that have shown variable success include wet combing, hot air treatments, and varying occlusive treatments. Physical removal via wet combing requires persistent repeated treatments over several weeks; for example, wet combing may be performed every 3 days for at least 2 weeks or until no head lice are detected on 4 consecutive occasions.³⁵ Cure rates range from 38% to 75% with wet combing as a sole treatment of head lice.³⁶ Because this treatment has minimal risks and no adverse side effects, it can be considered as an alternative treatment for some patients.

Hot air treatments also have been studied. A 2006 study showed that a hot air treatment device had the potential to eradicate head lice, most likely by desiccation. Specifically, 30 minutes of exposure to hot air (at 58.9°F, slightly cooler than a standard hair dryer) using the custom-built device resulted in 98% mortality of eggs and 80% mortality of hatched lice.³⁷ Large randomized controlled trials of hot air treatments have not been performed.

Other alternative treatments include plant-derived oils. A laboratory study of essential oils found that spearmint, cassia, and clove showed pediculicidal activity similar to malathion with improved ovicidal activity.³⁸ However, there is a potential for development of contact dermatitis from essential oils.

Complete Eradication of Head Lice
Removal of nits is an important component of effective lice eradication. Biochemical analysis has revealed that the nit sheath of the head louse is similar in composition to amyloid, rendering it difficult to design products that will unravel the nit sheath while leaving human hair undamaged.³⁹ Because pediculicides are not necessarily ovicidal and complete physical nit removal is difficult to achieve, re-treatment in 7 to 10 days often is advisable to ensure that lice in all stages of the life cycle have been killed.⁴ Treatment of any secondary bacterial infection also is important. Although transmission of lice via fomites is less likely than from head-to-head contact, the cleaning of hats, hairbrushes, and linens is prudent. Diagnosing and treating infested close contacts also is essential to achieving eradication.⁴ Coordinated surveillance, education, and treatment efforts in high-risk communities can help detect asymptomatic cases and control local epidemics in a cost-effective manner.⁴⁰ However, “no nit” policies at schools likely cause a net harm, as nit removal is difficult and children with nonviable nits are then excluded from the classroom.⁵

Treatment Resistance
Resistance to topical neurotoxic treatments is becoming increasingly common.^41-43 Therefore, it is important to identify local patterns of resistance, if possible, when selecting a therapy for head lice. Improper usage, changes in pediculicide formulations and packaging, decreased product efficacy, and natural selection have all contributed to this rise in resistance.⁷ Additionally, due to protection from multiple exoskeletons and the natural molting process as they mature into adults, nymphs may only receive a sublethal dose when exposed to pediculicides, contributing further to resistance.⁷ Resistance to synthetic pyrethroids is most predominant, likely due to selection pressure because permethrin historically has been the most widely used insecticide for pediculosis. A 2014 study found that the frequency of sodium-channel insensitivity to pyrethroids, also known as knockdown resistance (or kdr), in US head louse populations collected over a 10-year period was 84.4% and approached 100% in some communities in recent years.⁴⁴ This evidence strongly supports the use of alternative therapeutic categories to effectively eradicate head lice infestations.

Conclusion

Head lice infestation is common in children, and although it is not harmful to the host, it can be an irritating and symptomatic problem and can lead to notable distress, missed days of school, and secondary infections. Identifying active adult lice is the gold standard for diagnosis. Current recommended treatments include pyrethroids as the first-line therapy; however, resistance to these neurotoxic agents is becoming increasingly common. Alternative therapies such as newer neurotoxic agents or pediculicides with physical mechanisms of action (eg, dimethicone-based products) should be considered, particularly in regions where resistance is known to be high. Education about head lice, proper use of treatment, and coordinated diagnosis are necessary for effective management of this problem.

The head louse (Pediculus humanus capitis) is a blood-sucking arthropod of the suborder Anoplura. Lice are obligate human parasites that have infested humans since antiquity. Pediculosis capitis is an infestation of the scalp by head lice. It is estimated that 6 to 12 million individuals in the United States are affected with head lice per year.¹ Resistance to topical chemical pediculicides is widespread, and new agents have been developed to address this gap in care.

Characteristics of Head Lice

The head louse is a tan-gray–colored, wingless insect measuring approximately 2- to 3-mm long with 3 body segments. It has 6 legs with claws used to grasp individual hairs, and it moves by crawling; it does not fly or jump.^2,3 The head louse has an elongated abdomen and a small head with short antennae and anterior piercing mouthparts (Figure 1).⁴ Nits are transparent, flask-shaped, 0.5- to 0.8-mm egg cases found firmly cemented to the hair shafts approximately 1 to 4 mm above the level of the scalp (Figure 2).⁵ The head louse resides on scalp hair and feeds off the scalp itself. Both lice and nits can be present throughout the scalp but are most commonly found in the postauricular and occipital scalp.^3,4

Female lice live approximately 30 days and lay 5 to 10 eggs per day. Eggs incubate individually in nits laid close to the scalp for 8 to 10 days before hatching.^1,6 The newly hatched nymphs (also called instars) have multiple exoskeletons that are shed as they grow.⁷ Nymphs mature into adults in approximately 2 weeks, and the life cycle begins again.⁸ Head lice are obligate human parasites, feeding approximately every 4 to 6 hours on the blood of the host; however, they can survive up to 4 days without a blood meal on fomites if the climate and conditions are favorable.^5,9

Epidemiology and Transmission

Head lice infestations commonly occur in children aged 3 to 11 years and are more prevalent in girls and women.^1,10 Infestation rates are not reliably recorded, and few population-based studies have been performed; however, it is estimated that 6 to 12 million individuals are infested annually in the United States.¹ Prevalence in some European populations has been estimated to range from 1% to 20%.¹¹ A 2008 literature review found that worldwide prevalence varied across populations from 0.7% to 59%.¹⁰

Transmission occurs most frequently from direct head-to-head contact. One study found that transmission is most likely to occur when hairs are arranged in a parallel alignment and move slowly in relation to one another.¹² Although controversial and probably less notable, transmission also may occur indirectly via fomites or the sharing of hairbrushes, hats, or other headgear.^13,14 Classrooms are a common place for transmission.¹ A 2009 study in Germany found an increase in health department consultations for head lice when schools reopened after vacations. The investigators also found that pediculicide sales peaked from mid-September through October, subsequent to schools reopening after the summer holiday.¹⁵ There is some evidence that overcrowded housing also can lead to increased incidence and transmission.^16,17 There is no consistent correlation of infestation with socioeconomic status.^1,17,18

Clinical Manifestations and Diagnosis

Clinically, patients with head lice present with scalp pruritus and sometimes posterior cervical or occipital lymphadenopathy. Pediculosis also can be asymptomatic. With the first exposure, symptoms may not develop for up to 4 to 6 weeks as the immune system develops sensitivity to the louse saliva.⁶ Bite reactions consisting of papules or wheals are related to immune sensitization.⁵ Louse feces and excoriations from scratching to relieve itch also may be present on examination. Secondary infection of excoriations also is possible.¹

Diagnosis of an active infestation is made by identifying living lice. Because lice move quickly and can be difficult to detect, tightly attached nits on the hair shaft within 4 mm of the scalp are at least indicative of a historic infestation and can be suggestive of active infestation.^1,19 Dermoscopy is a helpful tool in differentiating eggs containing nymphs from the empty cases of hatched lice and also from amorphous pseudonits (hair casts)(Figure 3).^19,20 Wet combing improves the accuracy of diagnosing an active infection.²¹

Treatment

Effective treatment of head lice requires eradication of all living lice as well as louse eggs. Topically applied pyrethroids, including pyrethrin shampoos and mousses and permethrin lotion 1%, are considered the first-line therapy.⁸ Pyrethroids are over-the-counter treatments that act by interfering with sodium transport in the louse, causing depolarization of the neuromembranes and respiratory paralysis.²² Pyrethrins are natural compounds derived from the chrysanthemum plant; permethrin is a synthetic compound. Pyrethrins often are combined with piperonyl butoxide, an insecticide synergist that improves efficacy by inhibiting pyrethrin catabolism.²³ Resistance to pyrethroids has become an increasingly important problem in the United States and worldwide.

Malathion lotion 0.5% is another therapeutic option for head lice. Malathion is a prescription organophosphate cholinesterase inhibitor that also causes respiratory paralysis of the louse and is one of the few treatments that is ovicidal.²² It was withdrawn from the market in 1995 due to its flammability and a theoretical risk of respiratory depression if ingested; however, it was reintroduced in 1999 and remains an effective treatment option with little resistance in the United States.²⁴

Lindane 1% (shampoo and lotion), an organochloride compound that acts by causing neuronal hyperstimulation and eventual paralysis of lice, is no longer recommended due to its serious side effects, including central nervous system toxicity and increased risk of seizure.^8,24

New US Food and Drug Administration–Approved Therapies
Newer topical treatments include benzyl alcohol lotion 5%, spinosad topical suspension 0.9%, ivermectin lotion 0.5%, and dimethicone-based products. Benzyl alcohol was approved by the US Food and Drug Administration (FDA) in 2009 and is available in the United States by prescription.²⁵ Benzyl alcohol kills lice by asphyxiation. Phase 2 and 3 clinical trials showed significant treatment success 1 day posttreatment (fewer live lice than the vehicle alone; P=.004) and 2 weeks posttreatment (absence of live lice compared to the vehicle alone; P=.001).²⁶

Spinosad was approved by the FDA in 2011 and is available in the United States by prescription.²⁵ It contains the compounds spinosyn A and spinosyn D, which are naturally derived through fermentation by the soil bacterium Saccharopolyspora spinosa. It also contains benzyl alcohol. Spinosad paralyzes lice by disrupting neuronal activity and is at least partially ovicidal.²⁷ Phase 3 clinical trials published in 2009 showed that spinosad was significantly more effective than permethrin in eradicating head lice (P<.001).²⁸

Topical ivermectin was approved by the FDA in 2012 for prescription use.²⁵ It acts on chloride ion channels, causing hyperpolarization of the muscle cells of lice and resulting in paralysis and death. Oral ivermectin (200 μg/kg) given once and repeated in 10 days is not FDA approved for the treatment of head lice but has shown some effectiveness and is sometimes used.⁸ A comparison study of topical versus oral ivermectin published in 2014 found that eradication was achieved in 88% (n=27) of topical ivermectin users after 1 treatment and 100% (n=31) after 2 treatments. Oral ivermectin produced cure rates of 45% (n=14) after 1 treatment and 97% (n=30) after 2 treatments. Both topical and oral ivermectin treatments are well tolerated.²⁹

Physically Acting Preparations
Products with a physical mode of action are a new attractive option for treatment of pediculosis because the development of resistance is less likely. Studies of silicone-based fluids that physically occlude the respiratory system of the louse, such as dimethicone liquid gel 4%, have shown superiority over treatment with pyrethroids.^30,31 Although the safety of dimethicone has been demonstrated, silicone-based treatments have not yet been widely adopted in the United States and are not currently used as a first-line treatment.³² However, use of such physically acting pediculicides may in time surpass traditional neurotoxic treatments due to their low susceptibility to resistance and good safety profile.^33,34

Alternative Therapies
Nonchemical treatments for head lice that have shown variable success include wet combing, hot air treatments, and varying occlusive treatments. Physical removal via wet combing requires persistent repeated treatments over several weeks; for example, wet combing may be performed every 3 days for at least 2 weeks or until no head lice are detected on 4 consecutive occasions.³⁵ Cure rates range from 38% to 75% with wet combing as a sole treatment of head lice.³⁶ Because this treatment has minimal risks and no adverse side effects, it can be considered as an alternative treatment for some patients.

Hot air treatments also have been studied. A 2006 study showed that a hot air treatment device had the potential to eradicate head lice, most likely by desiccation. Specifically, 30 minutes of exposure to hot air (at 58.9°F, slightly cooler than a standard hair dryer) using the custom-built device resulted in 98% mortality of eggs and 80% mortality of hatched lice.³⁷ Large randomized controlled trials of hot air treatments have not been performed.

Other alternative treatments include plant-derived oils. A laboratory study of essential oils found that spearmint, cassia, and clove showed pediculicidal activity similar to malathion with improved ovicidal activity.³⁸ However, there is a potential for development of contact dermatitis from essential oils.

Complete Eradication of Head Lice
Removal of nits is an important component of effective lice eradication. Biochemical analysis has revealed that the nit sheath of the head louse is similar in composition to amyloid, rendering it difficult to design products that will unravel the nit sheath while leaving human hair undamaged.³⁹ Because pediculicides are not necessarily ovicidal and complete physical nit removal is difficult to achieve, re-treatment in 7 to 10 days often is advisable to ensure that lice in all stages of the life cycle have been killed.⁴ Treatment of any secondary bacterial infection also is important. Although transmission of lice via fomites is less likely than from head-to-head contact, the cleaning of hats, hairbrushes, and linens is prudent. Diagnosing and treating infested close contacts also is essential to achieving eradication.⁴ Coordinated surveillance, education, and treatment efforts in high-risk communities can help detect asymptomatic cases and control local epidemics in a cost-effective manner.⁴⁰ However, “no nit” policies at schools likely cause a net harm, as nit removal is difficult and children with nonviable nits are then excluded from the classroom.⁵

Treatment Resistance
Resistance to topical neurotoxic treatments is becoming increasingly common.^41-43 Therefore, it is important to identify local patterns of resistance, if possible, when selecting a therapy for head lice. Improper usage, changes in pediculicide formulations and packaging, decreased product efficacy, and natural selection have all contributed to this rise in resistance.⁷ Additionally, due to protection from multiple exoskeletons and the natural molting process as they mature into adults, nymphs may only receive a sublethal dose when exposed to pediculicides, contributing further to resistance.⁷ Resistance to synthetic pyrethroids is most predominant, likely due to selection pressure because permethrin historically has been the most widely used insecticide for pediculosis. A 2014 study found that the frequency of sodium-channel insensitivity to pyrethroids, also known as knockdown resistance (or kdr), in US head louse populations collected over a 10-year period was 84.4% and approached 100% in some communities in recent years.⁴⁴ This evidence strongly supports the use of alternative therapeutic categories to effectively eradicate head lice infestations.

Conclusion

Head lice infestation is common in children, and although it is not harmful to the host, it can be an irritating and symptomatic problem and can lead to notable distress, missed days of school, and secondary infections. Identifying active adult lice is the gold standard for diagnosis. Current recommended treatments include pyrethroids as the first-line therapy; however, resistance to these neurotoxic agents is becoming increasingly common. Alternative therapies such as newer neurotoxic agents or pediculicides with physical mechanisms of action (eg, dimethicone-based products) should be considered, particularly in regions where resistance is known to be high. Education about head lice, proper use of treatment, and coordinated diagnosis are necessary for effective management of this problem.

The head louse (Pediculus humanus capitis) is a blood-sucking arthropod of the suborder Anoplura. Lice are obligate human parasites that have infested humans since antiquity. Pediculosis capitis is an infestation of the scalp by head lice. It is estimated that 6 to 12 million individuals in the United States are affected with head lice per year.¹ Resistance to topical chemical pediculicides is widespread, and new agents have been developed to address this gap in care.

Characteristics of Head Lice

The head louse is a tan-gray–colored, wingless insect measuring approximately 2- to 3-mm long with 3 body segments. It has 6 legs with claws used to grasp individual hairs, and it moves by crawling; it does not fly or jump.^2,3 The head louse has an elongated abdomen and a small head with short antennae and anterior piercing mouthparts (Figure 1).⁴ Nits are transparent, flask-shaped, 0.5- to 0.8-mm egg cases found firmly cemented to the hair shafts approximately 1 to 4 mm above the level of the scalp (Figure 2).⁵ The head louse resides on scalp hair and feeds off the scalp itself. Both lice and nits can be present throughout the scalp but are most commonly found in the postauricular and occipital scalp.^3,4

Female lice live approximately 30 days and lay 5 to 10 eggs per day. Eggs incubate individually in nits laid close to the scalp for 8 to 10 days before hatching.^1,6 The newly hatched nymphs (also called instars) have multiple exoskeletons that are shed as they grow.⁷ Nymphs mature into adults in approximately 2 weeks, and the life cycle begins again.⁸ Head lice are obligate human parasites, feeding approximately every 4 to 6 hours on the blood of the host; however, they can survive up to 4 days without a blood meal on fomites if the climate and conditions are favorable.^5,9

Epidemiology and Transmission

Head lice infestations commonly occur in children aged 3 to 11 years and are more prevalent in girls and women.^1,10 Infestation rates are not reliably recorded, and few population-based studies have been performed; however, it is estimated that 6 to 12 million individuals are infested annually in the United States.¹ Prevalence in some European populations has been estimated to range from 1% to 20%.¹¹ A 2008 literature review found that worldwide prevalence varied across populations from 0.7% to 59%.¹⁰

Transmission occurs most frequently from direct head-to-head contact. One study found that transmission is most likely to occur when hairs are arranged in a parallel alignment and move slowly in relation to one another.¹² Although controversial and probably less notable, transmission also may occur indirectly via fomites or the sharing of hairbrushes, hats, or other headgear.^13,14 Classrooms are a common place for transmission.¹ A 2009 study in Germany found an increase in health department consultations for head lice when schools reopened after vacations. The investigators also found that pediculicide sales peaked from mid-September through October, subsequent to schools reopening after the summer holiday.¹⁵ There is some evidence that overcrowded housing also can lead to increased incidence and transmission.^16,17 There is no consistent correlation of infestation with socioeconomic status.^1,17,18

Clinical Manifestations and Diagnosis

Clinically, patients with head lice present with scalp pruritus and sometimes posterior cervical or occipital lymphadenopathy. Pediculosis also can be asymptomatic. With the first exposure, symptoms may not develop for up to 4 to 6 weeks as the immune system develops sensitivity to the louse saliva.⁶ Bite reactions consisting of papules or wheals are related to immune sensitization.⁵ Louse feces and excoriations from scratching to relieve itch also may be present on examination. Secondary infection of excoriations also is possible.¹

Diagnosis of an active infestation is made by identifying living lice. Because lice move quickly and can be difficult to detect, tightly attached nits on the hair shaft within 4 mm of the scalp are at least indicative of a historic infestation and can be suggestive of active infestation.^1,19 Dermoscopy is a helpful tool in differentiating eggs containing nymphs from the empty cases of hatched lice and also from amorphous pseudonits (hair casts)(Figure 3).^19,20 Wet combing improves the accuracy of diagnosing an active infection.²¹

Treatment

Effective treatment of head lice requires eradication of all living lice as well as louse eggs. Topically applied pyrethroids, including pyrethrin shampoos and mousses and permethrin lotion 1%, are considered the first-line therapy.⁸ Pyrethroids are over-the-counter treatments that act by interfering with sodium transport in the louse, causing depolarization of the neuromembranes and respiratory paralysis.²² Pyrethrins are natural compounds derived from the chrysanthemum plant; permethrin is a synthetic compound. Pyrethrins often are combined with piperonyl butoxide, an insecticide synergist that improves efficacy by inhibiting pyrethrin catabolism.²³ Resistance to pyrethroids has become an increasingly important problem in the United States and worldwide.

Malathion lotion 0.5% is another therapeutic option for head lice. Malathion is a prescription organophosphate cholinesterase inhibitor that also causes respiratory paralysis of the louse and is one of the few treatments that is ovicidal.²² It was withdrawn from the market in 1995 due to its flammability and a theoretical risk of respiratory depression if ingested; however, it was reintroduced in 1999 and remains an effective treatment option with little resistance in the United States.²⁴

Lindane 1% (shampoo and lotion), an organochloride compound that acts by causing neuronal hyperstimulation and eventual paralysis of lice, is no longer recommended due to its serious side effects, including central nervous system toxicity and increased risk of seizure.^8,24

New US Food and Drug Administration–Approved Therapies
Newer topical treatments include benzyl alcohol lotion 5%, spinosad topical suspension 0.9%, ivermectin lotion 0.5%, and dimethicone-based products. Benzyl alcohol was approved by the US Food and Drug Administration (FDA) in 2009 and is available in the United States by prescription.²⁵ Benzyl alcohol kills lice by asphyxiation. Phase 2 and 3 clinical trials showed significant treatment success 1 day posttreatment (fewer live lice than the vehicle alone; P=.004) and 2 weeks posttreatment (absence of live lice compared to the vehicle alone; P=.001).²⁶

Spinosad was approved by the FDA in 2011 and is available in the United States by prescription.²⁵ It contains the compounds spinosyn A and spinosyn D, which are naturally derived through fermentation by the soil bacterium Saccharopolyspora spinosa. It also contains benzyl alcohol. Spinosad paralyzes lice by disrupting neuronal activity and is at least partially ovicidal.²⁷ Phase 3 clinical trials published in 2009 showed that spinosad was significantly more effective than permethrin in eradicating head lice (P<.001).²⁸

Topical ivermectin was approved by the FDA in 2012 for prescription use.²⁵ It acts on chloride ion channels, causing hyperpolarization of the muscle cells of lice and resulting in paralysis and death. Oral ivermectin (200 μg/kg) given once and repeated in 10 days is not FDA approved for the treatment of head lice but has shown some effectiveness and is sometimes used.⁸ A comparison study of topical versus oral ivermectin published in 2014 found that eradication was achieved in 88% (n=27) of topical ivermectin users after 1 treatment and 100% (n=31) after 2 treatments. Oral ivermectin produced cure rates of 45% (n=14) after 1 treatment and 97% (n=30) after 2 treatments. Both topical and oral ivermectin treatments are well tolerated.²⁹

Physically Acting Preparations
Products with a physical mode of action are a new attractive option for treatment of pediculosis because the development of resistance is less likely. Studies of silicone-based fluids that physically occlude the respiratory system of the louse, such as dimethicone liquid gel 4%, have shown superiority over treatment with pyrethroids.^30,31 Although the safety of dimethicone has been demonstrated, silicone-based treatments have not yet been widely adopted in the United States and are not currently used as a first-line treatment.³² However, use of such physically acting pediculicides may in time surpass traditional neurotoxic treatments due to their low susceptibility to resistance and good safety profile.^33,34

Alternative Therapies
Nonchemical treatments for head lice that have shown variable success include wet combing, hot air treatments, and varying occlusive treatments. Physical removal via wet combing requires persistent repeated treatments over several weeks; for example, wet combing may be performed every 3 days for at least 2 weeks or until no head lice are detected on 4 consecutive occasions.³⁵ Cure rates range from 38% to 75% with wet combing as a sole treatment of head lice.³⁶ Because this treatment has minimal risks and no adverse side effects, it can be considered as an alternative treatment for some patients.

Hot air treatments also have been studied. A 2006 study showed that a hot air treatment device had the potential to eradicate head lice, most likely by desiccation. Specifically, 30 minutes of exposure to hot air (at 58.9°F, slightly cooler than a standard hair dryer) using the custom-built device resulted in 98% mortality of eggs and 80% mortality of hatched lice.³⁷ Large randomized controlled trials of hot air treatments have not been performed.

Other alternative treatments include plant-derived oils. A laboratory study of essential oils found that spearmint, cassia, and clove showed pediculicidal activity similar to malathion with improved ovicidal activity.³⁸ However, there is a potential for development of contact dermatitis from essential oils.

Complete Eradication of Head Lice
Removal of nits is an important component of effective lice eradication. Biochemical analysis has revealed that the nit sheath of the head louse is similar in composition to amyloid, rendering it difficult to design products that will unravel the nit sheath while leaving human hair undamaged.³⁹ Because pediculicides are not necessarily ovicidal and complete physical nit removal is difficult to achieve, re-treatment in 7 to 10 days often is advisable to ensure that lice in all stages of the life cycle have been killed.⁴ Treatment of any secondary bacterial infection also is important. Although transmission of lice via fomites is less likely than from head-to-head contact, the cleaning of hats, hairbrushes, and linens is prudent. Diagnosing and treating infested close contacts also is essential to achieving eradication.⁴ Coordinated surveillance, education, and treatment efforts in high-risk communities can help detect asymptomatic cases and control local epidemics in a cost-effective manner.⁴⁰ However, “no nit” policies at schools likely cause a net harm, as nit removal is difficult and children with nonviable nits are then excluded from the classroom.⁵

Treatment Resistance
Resistance to topical neurotoxic treatments is becoming increasingly common.^41-43 Therefore, it is important to identify local patterns of resistance, if possible, when selecting a therapy for head lice. Improper usage, changes in pediculicide formulations and packaging, decreased product efficacy, and natural selection have all contributed to this rise in resistance.⁷ Additionally, due to protection from multiple exoskeletons and the natural molting process as they mature into adults, nymphs may only receive a sublethal dose when exposed to pediculicides, contributing further to resistance.⁷ Resistance to synthetic pyrethroids is most predominant, likely due to selection pressure because permethrin historically has been the most widely used insecticide for pediculosis. A 2014 study found that the frequency of sodium-channel insensitivity to pyrethroids, also known as knockdown resistance (or kdr), in US head louse populations collected over a 10-year period was 84.4% and approached 100% in some communities in recent years.⁴⁴ This evidence strongly supports the use of alternative therapeutic categories to effectively eradicate head lice infestations.

Conclusion

Head lice infestation is common in children, and although it is not harmful to the host, it can be an irritating and symptomatic problem and can lead to notable distress, missed days of school, and secondary infections. Identifying active adult lice is the gold standard for diagnosis. Current recommended treatments include pyrethroids as the first-line therapy; however, resistance to these neurotoxic agents is becoming increasingly common. Alternative therapies such as newer neurotoxic agents or pediculicides with physical mechanisms of action (eg, dimethicone-based products) should be considered, particularly in regions where resistance is known to be high. Education about head lice, proper use of treatment, and coordinated diagnosis are necessary for effective management of this problem.

The use of JAK inhibitors is not the only notable development in the treatment of hair loss; light-based options show potential as well, according to Maria Hordinsky, MD.

“Although the precise mechanism remains unclear, it has been postulated that photobiomodulation acts through oxidative metabolism and transcription factor stimulation,” Dr. Hordinsky said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

The use of JAK inhibitors is not the only notable development in the treatment of hair loss; light-based options show potential as well, according to Maria Hordinsky, MD.

“Although the precise mechanism remains unclear, it has been postulated that photobiomodulation acts through oxidative metabolism and transcription factor stimulation,” Dr. Hordinsky said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

The use of JAK inhibitors is not the only notable development in the treatment of hair loss; light-based options show potential as well, according to Maria Hordinsky, MD.

“Although the precise mechanism remains unclear, it has been postulated that photobiomodulation acts through oxidative metabolism and transcription factor stimulation,” Dr. Hordinsky said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

Categorizing hair loss in children depends on many factors, but it is important to rule out an infectious etiology as early as possible, according to Sheila Fallon Friedlander, MD.

“What can Tinea capitis look like? Anything,” she said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

Although T. capitis most often presents in children aged 3-7 years as a pattern of localized hair loss, often with scaling, sometimes with nodules, other possibilities include pustules, boggy masses, and diffuse hair loss, said Dr. Friedlander, professor of pediatrics and dermatology at the University of California, San Diego.

Sometimes the hair loss may be so subtle that families come in complaining of “dandruff” rather than hair loss, she noted. Evaluating the patient for the presence of cervical or occipital lymph nodes is crucial; big nodes are usually a tip-off that infection is present.

The optimal treatment plan for T. capitis depends on the source, Dr. Friedlander explained. If M. canis is the cause, “griseofulvin is the drug of choice,” along with a twice-weekly sporicidal shampoo, she said.

Other treatment options include terbinafine, itraconazole, and fluconazole, and each have their pros and cons, she said. Terbinafine – which persists for months in the skin, nails, and hair – is the least expensive, and is her first choice for infections caused by T. tonsurans.

Itraconazole is available as a liquid, but costs more, causes diarrhea, and comes with a boxed warning about the potential for cardiac complications; fluconazole is the most expensive, but may be used in infants, she added.

Other high-risk groups for T. capitis include female caretakers of high-risk individuals, such as “grandma”; wrestlers; and Buddhist monks, she said. “Short hair, sharing combs, and unclean barbers” contributed to a documented increased risk of T. capitis according to a recently published study of 60 Buddhist monks whose average age was 11.6 years, she added. (Pediatr Dermatol. 2017 May;34[3]:371-3).

Dr. Friedlander had no relevant financial conflicts to disclose.

SDEF and this news organization are owned by Frontline Medical Communications.

Categorizing hair loss in children depends on many factors, but it is important to rule out an infectious etiology as early as possible, according to Sheila Fallon Friedlander, MD.

“What can Tinea capitis look like? Anything,” she said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

Although T. capitis most often presents in children aged 3-7 years as a pattern of localized hair loss, often with scaling, sometimes with nodules, other possibilities include pustules, boggy masses, and diffuse hair loss, said Dr. Friedlander, professor of pediatrics and dermatology at the University of California, San Diego.

Sometimes the hair loss may be so subtle that families come in complaining of “dandruff” rather than hair loss, she noted. Evaluating the patient for the presence of cervical or occipital lymph nodes is crucial; big nodes are usually a tip-off that infection is present.

The optimal treatment plan for T. capitis depends on the source, Dr. Friedlander explained. If M. canis is the cause, “griseofulvin is the drug of choice,” along with a twice-weekly sporicidal shampoo, she said.

Other treatment options include terbinafine, itraconazole, and fluconazole, and each have their pros and cons, she said. Terbinafine – which persists for months in the skin, nails, and hair – is the least expensive, and is her first choice for infections caused by T. tonsurans.

Itraconazole is available as a liquid, but costs more, causes diarrhea, and comes with a boxed warning about the potential for cardiac complications; fluconazole is the most expensive, but may be used in infants, she added.

Other high-risk groups for T. capitis include female caretakers of high-risk individuals, such as “grandma”; wrestlers; and Buddhist monks, she said. “Short hair, sharing combs, and unclean barbers” contributed to a documented increased risk of T. capitis according to a recently published study of 60 Buddhist monks whose average age was 11.6 years, she added. (Pediatr Dermatol. 2017 May;34[3]:371-3).

Dr. Friedlander had no relevant financial conflicts to disclose.

SDEF and this news organization are owned by Frontline Medical Communications.

Categorizing hair loss in children depends on many factors, but it is important to rule out an infectious etiology as early as possible, according to Sheila Fallon Friedlander, MD.

“What can Tinea capitis look like? Anything,” she said in a presentation at Skin Disease Education Foundation’s Women’s & Pediatric Dermatology Seminar.

Although T. capitis most often presents in children aged 3-7 years as a pattern of localized hair loss, often with scaling, sometimes with nodules, other possibilities include pustules, boggy masses, and diffuse hair loss, said Dr. Friedlander, professor of pediatrics and dermatology at the University of California, San Diego.

Sometimes the hair loss may be so subtle that families come in complaining of “dandruff” rather than hair loss, she noted. Evaluating the patient for the presence of cervical or occipital lymph nodes is crucial; big nodes are usually a tip-off that infection is present.

The optimal treatment plan for T. capitis depends on the source, Dr. Friedlander explained. If M. canis is the cause, “griseofulvin is the drug of choice,” along with a twice-weekly sporicidal shampoo, she said.

Other treatment options include terbinafine, itraconazole, and fluconazole, and each have their pros and cons, she said. Terbinafine – which persists for months in the skin, nails, and hair – is the least expensive, and is her first choice for infections caused by T. tonsurans.

Itraconazole is available as a liquid, but costs more, causes diarrhea, and comes with a boxed warning about the potential for cardiac complications; fluconazole is the most expensive, but may be used in infants, she added.

Other high-risk groups for T. capitis include female caretakers of high-risk individuals, such as “grandma”; wrestlers; and Buddhist monks, she said. “Short hair, sharing combs, and unclean barbers” contributed to a documented increased risk of T. capitis according to a recently published study of 60 Buddhist monks whose average age was 11.6 years, she added. (Pediatr Dermatol. 2017 May;34[3]:371-3).

Dr. Friedlander had no relevant financial conflicts to disclose.

SDEF and this news organization are owned by Frontline Medical Communications.

CHICAGO – Maral Skelsey, MD, doesn’t get flowers from her patients very often. But, she said, a big bouquet recently landed on her desk after she had performed a nail biopsy on a patient. The note from the patient read, “That wasn’t as bad as I thought it would be!”

The patient’s relief after the procedure highlights the apprehension that both patients and dermatologists can feel when a nail biopsy becomes necessary, said Dr. Skelsey, director of dermatologic surgery at Georgetown University, Washington, D.C.

Speaking at the summer meeting of the American Academy of Dermatology, Dr. Skelsey said that the most important advice she can give about the nail biopsy is, “Do it early and often.”

Dr. Skelsey reminded the audience that the musician Bob Marley died of malignant melanoma; the first sign of his cancer was a longitudinal melanonychia that went unbiopsied. “The biggest mistake we make is not doing it,” she said.

In performing a nail biopsy, said Dr. Skelsey, the goals are, first and foremost, to optimize the pathologic diagnosis. Correct technique can help avoid complications such as bleeding, infection, and nail dystrophy; the right approach can minimize pain and anxiety, she added.

In preparing for a biopsy for melanonychia, “dermoscopy can be very helpful” in assessing the location of the pigment and fine-tuning planning for the biopsy, said Dr. Skelsey. Also, if the streak of melanonychia has reached the distal nail, sending the clipping for pathology can be useful as well.

For dorsal pigmentation, the proximal nail matrix should be biopsied.

“Do not use a punch biopsy on the nail fold to diagnose melanoma – you will get a false negative,” Dr. Skelsey said. It’s not possible to get an accurate diagnosis going through the nail plate to the nail bed, she said.

The preoperative assessment is usually straightforward. Pertinent items in the patient’s history include any medication allergies, current anticoagulation, and any history of prior trauma to the digit to be biopsied. Occasionally, imaging may be helpful, and patients should always be assessed for vascular insufficiency, she noted.

Preoperatively, she asks her patients to remove nail polish and pretreat the area with povidone iodine for 2 days prior to the procedure. Patients need to have a ride home after the procedure, and should be prepared to elevate the affected extremity for 48 hours post procedure. If a toenail is biopsied, they’re advised to come with a postop shoe.

Her patients receive a 5-minute isopropyl alcohol wash of the area to be biopsied just before the procedure, followed by air drying and a 5-minute scrub with 7.5% povidone iodine, which then is wiped off preprocedure.

For hemostasis, a tourniquet can be improvised with a sterile glove finger and a hemostat; there are also dedicated finger cots available that work well for this purpose, she said. In addition to nail nippers and a nail elevator, an English nail splitter can be helpful, said Dr. Skelsey.

For anesthesia, she said she ordinarily uses a 30 gauge needle with buffered lidocaine and epinephrine at room temperature to deliver a wing block. Beginning about 1 cm proximal and lateral to the junction of the proximal and lateral nail fold, the dermatologist can slowly inject about 1.5 cc per side. As the block takes effect, the lateral nail fold will blanch distally in a wing-shaped pattern. This technique, she said, also has the benefit of acting as a volumetric tourniquet.

“To avulse or not to avulse?” asked Dr. Skelsey. “I used to avulse almost everything,” she said, but noted that a complete avulsion is a “pretty traumatic” procedure. Now, unless a full avulsion is required for complete and accurate pathology, she will usually perform a partial nail plate avulsion.

A partial avulsion can reduce pain and morbidity, and can be done by two different methods: the partial proximal avulsion, and the “trap door” avulsion. In a trap door avulsion, she said, the distal matrix is primarily visualized, so this may be a good option for a longitudinal melanonychia arising from the distal matrix. A Freer elevator is used to detach the nail plate from the bed and the matrix, after which the nail plate can be lifted with a hemostat.

In a partial proximal avulsion, the proximal nail fold is reflected, so it’s a better option when the proximal nail matrix needs evaluation, she said.

After the avulsion has been done, “the matrix has been exposed. Now what? Punch or shave?” asked Dr. Skelsey. She noted that she used to perform punch biopsies on “everything,” and that it’s a good option if the pigmented area spans 3 mm or less. One issue, though, is that the specimen can get stuck in the puncher, and extraction can make it difficult to deliver an intact specimen.

Shave biopsies, Dr. Skelsey said, are effective in dealing with nail matrix lesions. They can yield an accurate pathologic diagnosis, and the biopsied digits healed without nail dystrophy in about three quarters of the cases in one study, she said. Potential recurrence of pigmentation is one drawback of the shave technique, she said.

With a shave biopsy, she performs tangential incisions of the proximal and lateral nail folds, and scores and reflects the nail. Then, the band of pigment is shaved tangentially. She cauterizes the area, and sometimes will use a bit of an absorbable gelatin sponge (Gelfoam) as well. Then the proximal nail fold and nail plate are sutured.

Replacing the nail plate results in better cosmesis and is much more comfortable for the patient, she said. An 18-gauge needle can be used to bore a hole through the avulsed nail plate, which may be held in an antiseptic solution soak during the biopsy. The sutures should then be placed from skin to nail plate, so nail fragments aren’t driven into the skin during the suturing process. Finally, specimen margins should be inked, and separate labeled formalin jars are needed for the nail plate, nail bed, and the matrix.

Dr. Skelsey reported that she had no conflicts of interest.
 

[email protected]

On Twitter @karioakes

CHICAGO – Maral Skelsey, MD, doesn’t get flowers from her patients very often. But, she said, a big bouquet recently landed on her desk after she had performed a nail biopsy on a patient. The note from the patient read, “That wasn’t as bad as I thought it would be!”

The patient’s relief after the procedure highlights the apprehension that both patients and dermatologists can feel when a nail biopsy becomes necessary, said Dr. Skelsey, director of dermatologic surgery at Georgetown University, Washington, D.C.

Speaking at the summer meeting of the American Academy of Dermatology, Dr. Skelsey said that the most important advice she can give about the nail biopsy is, “Do it early and often.”

Dr. Skelsey reminded the audience that the musician Bob Marley died of malignant melanoma; the first sign of his cancer was a longitudinal melanonychia that went unbiopsied. “The biggest mistake we make is not doing it,” she said.

In performing a nail biopsy, said Dr. Skelsey, the goals are, first and foremost, to optimize the pathologic diagnosis. Correct technique can help avoid complications such as bleeding, infection, and nail dystrophy; the right approach can minimize pain and anxiety, she added.

In preparing for a biopsy for melanonychia, “dermoscopy can be very helpful” in assessing the location of the pigment and fine-tuning planning for the biopsy, said Dr. Skelsey. Also, if the streak of melanonychia has reached the distal nail, sending the clipping for pathology can be useful as well.

For dorsal pigmentation, the proximal nail matrix should be biopsied.

“Do not use a punch biopsy on the nail fold to diagnose melanoma – you will get a false negative,” Dr. Skelsey said. It’s not possible to get an accurate diagnosis going through the nail plate to the nail bed, she said.

The preoperative assessment is usually straightforward. Pertinent items in the patient’s history include any medication allergies, current anticoagulation, and any history of prior trauma to the digit to be biopsied. Occasionally, imaging may be helpful, and patients should always be assessed for vascular insufficiency, she noted.

Preoperatively, she asks her patients to remove nail polish and pretreat the area with povidone iodine for 2 days prior to the procedure. Patients need to have a ride home after the procedure, and should be prepared to elevate the affected extremity for 48 hours post procedure. If a toenail is biopsied, they’re advised to come with a postop shoe.

Her patients receive a 5-minute isopropyl alcohol wash of the area to be biopsied just before the procedure, followed by air drying and a 5-minute scrub with 7.5% povidone iodine, which then is wiped off preprocedure.

For hemostasis, a tourniquet can be improvised with a sterile glove finger and a hemostat; there are also dedicated finger cots available that work well for this purpose, she said. In addition to nail nippers and a nail elevator, an English nail splitter can be helpful, said Dr. Skelsey.

For anesthesia, she said she ordinarily uses a 30 gauge needle with buffered lidocaine and epinephrine at room temperature to deliver a wing block. Beginning about 1 cm proximal and lateral to the junction of the proximal and lateral nail fold, the dermatologist can slowly inject about 1.5 cc per side. As the block takes effect, the lateral nail fold will blanch distally in a wing-shaped pattern. This technique, she said, also has the benefit of acting as a volumetric tourniquet.

“To avulse or not to avulse?” asked Dr. Skelsey. “I used to avulse almost everything,” she said, but noted that a complete avulsion is a “pretty traumatic” procedure. Now, unless a full avulsion is required for complete and accurate pathology, she will usually perform a partial nail plate avulsion.

A partial avulsion can reduce pain and morbidity, and can be done by two different methods: the partial proximal avulsion, and the “trap door” avulsion. In a trap door avulsion, she said, the distal matrix is primarily visualized, so this may be a good option for a longitudinal melanonychia arising from the distal matrix. A Freer elevator is used to detach the nail plate from the bed and the matrix, after which the nail plate can be lifted with a hemostat.

In a partial proximal avulsion, the proximal nail fold is reflected, so it’s a better option when the proximal nail matrix needs evaluation, she said.

After the avulsion has been done, “the matrix has been exposed. Now what? Punch or shave?” asked Dr. Skelsey. She noted that she used to perform punch biopsies on “everything,” and that it’s a good option if the pigmented area spans 3 mm or less. One issue, though, is that the specimen can get stuck in the puncher, and extraction can make it difficult to deliver an intact specimen.

Shave biopsies, Dr. Skelsey said, are effective in dealing with nail matrix lesions. They can yield an accurate pathologic diagnosis, and the biopsied digits healed without nail dystrophy in about three quarters of the cases in one study, she said. Potential recurrence of pigmentation is one drawback of the shave technique, she said.

With a shave biopsy, she performs tangential incisions of the proximal and lateral nail folds, and scores and reflects the nail. Then, the band of pigment is shaved tangentially. She cauterizes the area, and sometimes will use a bit of an absorbable gelatin sponge (Gelfoam) as well. Then the proximal nail fold and nail plate are sutured.

Replacing the nail plate results in better cosmesis and is much more comfortable for the patient, she said. An 18-gauge needle can be used to bore a hole through the avulsed nail plate, which may be held in an antiseptic solution soak during the biopsy. The sutures should then be placed from skin to nail plate, so nail fragments aren’t driven into the skin during the suturing process. Finally, specimen margins should be inked, and separate labeled formalin jars are needed for the nail plate, nail bed, and the matrix.

Dr. Skelsey reported that she had no conflicts of interest.
 

[email protected]

On Twitter @karioakes

CHICAGO – Maral Skelsey, MD, doesn’t get flowers from her patients very often. But, she said, a big bouquet recently landed on her desk after she had performed a nail biopsy on a patient. The note from the patient read, “That wasn’t as bad as I thought it would be!”

The patient’s relief after the procedure highlights the apprehension that both patients and dermatologists can feel when a nail biopsy becomes necessary, said Dr. Skelsey, director of dermatologic surgery at Georgetown University, Washington, D.C.

Speaking at the summer meeting of the American Academy of Dermatology, Dr. Skelsey said that the most important advice she can give about the nail biopsy is, “Do it early and often.”

Dr. Skelsey reminded the audience that the musician Bob Marley died of malignant melanoma; the first sign of his cancer was a longitudinal melanonychia that went unbiopsied. “The biggest mistake we make is not doing it,” she said.

In performing a nail biopsy, said Dr. Skelsey, the goals are, first and foremost, to optimize the pathologic diagnosis. Correct technique can help avoid complications such as bleeding, infection, and nail dystrophy; the right approach can minimize pain and anxiety, she added.

In preparing for a biopsy for melanonychia, “dermoscopy can be very helpful” in assessing the location of the pigment and fine-tuning planning for the biopsy, said Dr. Skelsey. Also, if the streak of melanonychia has reached the distal nail, sending the clipping for pathology can be useful as well.

For dorsal pigmentation, the proximal nail matrix should be biopsied.

“Do not use a punch biopsy on the nail fold to diagnose melanoma – you will get a false negative,” Dr. Skelsey said. It’s not possible to get an accurate diagnosis going through the nail plate to the nail bed, she said.

The preoperative assessment is usually straightforward. Pertinent items in the patient’s history include any medication allergies, current anticoagulation, and any history of prior trauma to the digit to be biopsied. Occasionally, imaging may be helpful, and patients should always be assessed for vascular insufficiency, she noted.

Preoperatively, she asks her patients to remove nail polish and pretreat the area with povidone iodine for 2 days prior to the procedure. Patients need to have a ride home after the procedure, and should be prepared to elevate the affected extremity for 48 hours post procedure. If a toenail is biopsied, they’re advised to come with a postop shoe.

Her patients receive a 5-minute isopropyl alcohol wash of the area to be biopsied just before the procedure, followed by air drying and a 5-minute scrub with 7.5% povidone iodine, which then is wiped off preprocedure.

For hemostasis, a tourniquet can be improvised with a sterile glove finger and a hemostat; there are also dedicated finger cots available that work well for this purpose, she said. In addition to nail nippers and a nail elevator, an English nail splitter can be helpful, said Dr. Skelsey.

For anesthesia, she said she ordinarily uses a 30 gauge needle with buffered lidocaine and epinephrine at room temperature to deliver a wing block. Beginning about 1 cm proximal and lateral to the junction of the proximal and lateral nail fold, the dermatologist can slowly inject about 1.5 cc per side. As the block takes effect, the lateral nail fold will blanch distally in a wing-shaped pattern. This technique, she said, also has the benefit of acting as a volumetric tourniquet.

“To avulse or not to avulse?” asked Dr. Skelsey. “I used to avulse almost everything,” she said, but noted that a complete avulsion is a “pretty traumatic” procedure. Now, unless a full avulsion is required for complete and accurate pathology, she will usually perform a partial nail plate avulsion.

A partial avulsion can reduce pain and morbidity, and can be done by two different methods: the partial proximal avulsion, and the “trap door” avulsion. In a trap door avulsion, she said, the distal matrix is primarily visualized, so this may be a good option for a longitudinal melanonychia arising from the distal matrix. A Freer elevator is used to detach the nail plate from the bed and the matrix, after which the nail plate can be lifted with a hemostat.

In a partial proximal avulsion, the proximal nail fold is reflected, so it’s a better option when the proximal nail matrix needs evaluation, she said.

After the avulsion has been done, “the matrix has been exposed. Now what? Punch or shave?” asked Dr. Skelsey. She noted that she used to perform punch biopsies on “everything,” and that it’s a good option if the pigmented area spans 3 mm or less. One issue, though, is that the specimen can get stuck in the puncher, and extraction can make it difficult to deliver an intact specimen.

Shave biopsies, Dr. Skelsey said, are effective in dealing with nail matrix lesions. They can yield an accurate pathologic diagnosis, and the biopsied digits healed without nail dystrophy in about three quarters of the cases in one study, she said. Potential recurrence of pigmentation is one drawback of the shave technique, she said.

With a shave biopsy, she performs tangential incisions of the proximal and lateral nail folds, and scores and reflects the nail. Then, the band of pigment is shaved tangentially. She cauterizes the area, and sometimes will use a bit of an absorbable gelatin sponge (Gelfoam) as well. Then the proximal nail fold and nail plate are sutured.

Replacing the nail plate results in better cosmesis and is much more comfortable for the patient, she said. An 18-gauge needle can be used to bore a hole through the avulsed nail plate, which may be held in an antiseptic solution soak during the biopsy. The sutures should then be placed from skin to nail plate, so nail fragments aren’t driven into the skin during the suturing process. Finally, specimen margins should be inked, and separate labeled formalin jars are needed for the nail plate, nail bed, and the matrix.

Dr. Skelsey reported that she had no conflicts of interest.
 

[email protected]

On Twitter @karioakes

Onychomycosis is a fungal nail infection primarily caused by dermatophytes.¹ If left untreated, the infection can cause nail destruction and deformities,¹ resulting in pain and discomfort,² impaired foot mobility,³ and an overall reduced quality of life.¹ Onychomycosis is a chronic condition that requires long treatment periods due to the slow growth rates of toenails.¹ To successfully cure the condition, fungal eradication must be achieved.

Prior to the US Food and Drug Administration (FDA) approval of tavaborole and efinaconazole, ciclopirox was the only approved topical treatment for onychomycosis.⁴ The recent approval of tavaborole and efinaconazole has increased treatment options available to patients and has started to pave the way for future topical treatments. This article discusses the 3 approved topical treatments for onychomycosis and focuses on the design of the phase 3 clinical trials that led to their approval.

Topical Agents Used to Treat Onychomycosis

Tavaborole, efinaconazole, and ciclopirox have undergone extensive clinical investigation to receive FDA approval. Results from pivotal phase 3 studies establishing the efficacy and safety of each agent formed the basis for regulatory submission. Although it may seem intuitive to compare the relative performance of these agents based on their respective phase 3 clinical trial data, there are important differences in study methodology, conduct, and populations that prevent direct comparisons. The FDA provides limited guidance to the pharmaceutical industry on how to conduct clinical trials for potential onychomycosis treatments. Comparative efficacy and safety claims are limited based on cross-study comparisons. The details of the phase 3 trial designs are summarized in the Table.

Tavaborole
Tavaborole is a boron-based treatment with a novel mechanism of action.⁵ Tavaborole binds to the editing domain of leucyl–transfer ribonucleic acid synthetase via an integrated boron atom and inhibits fungal protein synthesis.⁶ Two identical randomized, double-blind, vehicle-controlled, parallel-group, phase 3 clinical trials evaluating tavaborole were performed.⁵ The first study (registered at www.clinicaltrials.gov with the identifier NCT01270971) included 594 participants from27 sites in the United States and Mexico and was conducted between December 2010 and November 2012. The second study (NCT01302119) included 604 participants from 32 sites in the United States and Canada and was conducted between February 2011 and January 2013.

Eligible participants 18 years and older had distal subungual onychomycosis (DSO) of the toenails affecting 20% to 60% of 1 or more target great toenails (TGTs), tested positive for fungus using potassium hydroxide (KOH) wet mounts and positive for Trichophyton rubrum and Trichophyton mentagrophytes on fungal culture diagnostic tests, had distal TGT thickness of 3 mm or less, and had 3 mm or more of clear nail between the proximal nail fold and the most proximal visible mycotic border.⁵ Those with active tinea pedis requiring treatment or with a history of chronic moccasin-type tinea pedis were excluded. Participants were randomized to receive either tavaborole or vehicle (2:1). Treatments were applied once daily to all infected toenails for a total of 48 weeks, and nail debridement (defined as partial or complete removal of the toenail) was not permitted. Notably, controlled trimming of the nail was allowed to 1 mm of the leading nail edge. Regular assessments of each toenail for disease involvement, onycholysis, and subungual hyperkeratosis were made at screening, baseline, week 2, week 6, and every 6 weeks thereafter until week 52. Subungual TGT samples were taken at screening and every 12 weeks during the study for examination at a mycology laboratory, which performed KOH and fungal culture tests. A follow-up assessment was made at week 52.⁵

The primary end point was complete cure of the TGT at week 52, with secondary end points of completely or almost clear TGT nail (≤10% dystrophic nail), completely or almost clear TGT nail (≤10% dystrophic nail) plus negative mycology, and negative mycology of TGT.⁵ Examples of TGTs in participants who achieved complete cure and almost clear nails with negative mycology before and after treatment with tavaborole are shown in Figure 1. An example of a patient considered to have treatment failure is shown in Figure 2. This patient showed marked improvement in nail appearance and had a negative culture result but had a positive KOH test, which demonstrates the stringency in which topical agents are judged in onychomycosis trials.⁵

Efinaconazole
Efinaconazole is a topical triazole antifungal specifically indicated to treat onychomycosis. Two identical randomized, vehicle-controlled, double-blind, multicenter trials were performed to assess the safety and efficacy of efinaconazole solution 10%^.7 The first study (NCT01008033) involved 870 participants and was conducted at a total of 74 sites in Japan (33 sites), Canada (7 sites), and the United States (34 sites) between December 2009 and September 2011. The second study (NCT01007708) had 785 participants and was conducted at 44 sites in Canada (8 sites) and the United States (36 sites) between December 2009 and October 2011.

Participants aged 18 to 70 years with a clinical diagnosis of DSO affecting 1 or more TGT were eligible to participate.⁷ Other eligibility criteria included an uninfected toenail length 3 mm or more from the proximal nail fold, a maximum toenail thickness of 3 mm, positive KOH wet mounts, and positive dermatophyte or mixed dermatophyte/candida cultures. Dermatophytes included T rubrum and T mentagrophytes. Those with severe moccasin-type tinea pedis were excluded. Participants were randomized to receive efinaconazole or vehicle (3:1). Once-daily treatments were self-applied to nails for 48 weeks. Clinical assessments were made at baseline and every 12 weeks until week 48, with a follow-up assessment at week 52. No nail trimming protocol was provided.⁷

The primary end point of the efinaconazole phase 3 trials was complete cure at week 52, with secondary end points including mycologic cure, treatment success (≤5% mycotic nail), and complete or almost complete cure (negative culture and KOH, ≤5% mycotic nail). An example of a complete cure from baseline to week 52 is shown in Figure 3.⁷

Ciclopirox
Ciclopirox was the first topical therapy to be approved for the treatment of onychomycosis. Ciclopirox is a broad-spectrum antifungal agent that inhibits metal-dependent enzymes, which are responsible for the degradation of toxic peroxides in fungal cells. The safety and efficacy of ciclopirox nail lacquer topical solution 8% also was investigated in 2 identical phase 3 clinical trials.⁸ The first study was conducted at 9 sites in the United States between June 1994 and June 1996 and included 223 participants. The second study was conducted at 9 sites in the United States between July 1994 and April 1996 and included 237 participants.

Eligible participants were required to have DSO in at least one TGT, positive KOH wet mount with positive dermatophyte culture, and 20% to 65% nail involvement.⁸ Those with tinea pedis were not excluded. Participants were randomized to receive once-daily treatment with ciclopirox or vehicle (1:1)(applied to all toenails and affected fingernails) for 48 weeks. The product was to be removed by the patient with alcohol on a weekly basis. Trimming was allowed as necessary, and mechanical debridement by the physician could be performed monthly. Assessments were made every 4 weeks, and mycologic examinations were performed every 12 weeks. Participants who were clinically cured were assessed further in a 12- to 24-week posttreatment follow-up period.⁸

The primary end point of complete cure and secondary end points of treatment success (negative culture and KOH, ≤10% mycotic nail), mycologic cure, and negative mycologic culture were assessed at week 48.⁸

Phase 3 Clinical Trial Similarities and Differences

The phase 3 clinical trials used to investigate the safety and efficacy of tavaborole,⁵ efinaconazole,⁷ and ciclopirox⁸ were similar in their overall design. All trials were randomized, double-blind, vehicle-controlled studies in patients with DSO. Each agent was assessed using a once-daily application for a treatment period of 48 weeks.

Primary differences among study designs included the age range of participants, the range of mycotic nail involvement, the presence/absence of tinea pedis, and the nail trimming/debridement protocols used. Differences were observed in the patient eligibility criteria of these trials. Both mycotic area and participant age range were inconsistent for each agent (eTable). Participants with larger mycotic areas usually have a poorer prognosis, as they tend to have a greater fungal load.⁹ A baseline mycotic area of 20% to 60%,⁵ 20% to 50%,⁷ and 20% to 65%⁸ at baseline was required for the tavaborole, efinaconazole, and ciclopirox trials, respectively. Variations in mycotic area between trials can affect treatment efficacy, as clinical cures can be reached quicker by patients with smaller areas of infection. Of note, the average mycotic area of involvement was not reported in the tavaborole studies but was 36% and 40% for the efinaconazole and ciclopirox studies, respectively.^5,8 It also is more difficult to achieve complete cure in older patients, as they have poor circulation and reduced nail growth rates.^1,10 The participant age range was 18 to 88 years in the tavaborole trials, with 8% of the participants older than 70 years,⁵ compared to 18 to 71 years in both the efinaconazole and ciclopirox trials.^7,8 The average age of participants in each study was approximately 54, 51, and 50 years for tavaborole, efinaconazole, and ciclopirox, respectively. Because factors impacting treatment failure can increase with age, efficacy results can be confounded by differing age distributions across different studies.

Another important feature that differed between the clinical trials was the approach to nail trimming—defined as shortening of the free edge of the nail distal to the hyponychium—which varies from debridement in that the nail plate is removed or reduced in thickness proximal to the hyponychium. In the tavaborole trials, trimming was controlled to within 1 mm of the free edge of the nail,⁵ whereas the protocol used for the ciclopirox trials allowed nail trimming as necessary as well as moderate debridement before treatment application and on a monthly basis.⁸ Debridement is an important component in all ciclopirox trials, as it is used to reduce fungal load.¹¹ No trimming control was provided during the efinaconazole trials; however, debridement was prohibited.⁷ These differences can dramatically affect the study results, as residual fungal elements and portions of infected nails are removed during the trimming process in an uncontrolled manner, which can affect mycologic testing results as well as the clinical efficacy results determined through investigator evaluation. Discrepancies regarding nail trimming approach inevitably makes the trial results difficult to compare, as mycologic cure is not translatable between studies.

Furthermore, somewhat unusually, complete cure rate variations were observed between different study centers in the efinaconazole trials. Japanese centers in the first efinaconazole study (NCT01008033) had higher complete cure rates in both the efinaconazole and vehicle treatment arms, which is notable because approximately 29% of participants in this study were Asian, mostly hailing from 33 Japanese centers. The reason for these confounding results is unknown and requires further analysis.

Lastly, the presence or absence of tinea pedis can affect the response to onychomycosis treatment. In the tavaborole trials, patients with active interdigital tinea pedis or exclusively plantar tinea pedis or chronic moccasin-type tinea pedis requiring treatment were excluded from the studies.⁵ In contrast, only patients with severe moccasin-type tinea pedis were excluded in efinaconazole trials.⁷ The ciclopirox studies had no exclusions based on presence of tinea pedis.⁸ These differences are noteworthy, as tinea pedis can serve as a reservoir for fungal infection if not treated and can lead to recurrence of onychomycosis.¹²

Conclusion

In recent years, disappointing efficacy has resulted in the failure of several topical agents for onychomycosis during their development; however, there are several aspects to consider when examining efficacy data in onychomycosis studies. Obtaining a complete cure in onychomycosis is difficult. Because patients applying treatments at home are unlikely to undergo mycologic testing to confirm complete cure, visual inspections are helpful to determine treatment efficacy.

Despite similar overall designs, notable differences in the study designs of the phase 3 clinical trials investigating tavaborole, efinaconazole, and ciclopirox are likely to have had an effect on the reported results, making the efficacy of the agents difficult to compare. It is particularly tempting to compare the primary end point results of each trial, especially considering tavaborole and efinaconazole had primary end points with the same parameters; however, there are several other factors (eg, age range of study population, extent of infection, nail trimming, patient demographics) that may have affected the outcomes of the studies and precluded a direct comparison of any end points. Without head-to-head investigations, there is room for prescribing clinicians to interpret results differently.

Acknowledgment

Writing and editorial assistance was provided by ApotheCom Associates, LLC, Yardley, Pennsylvania, and was supported by Sandoz, a Novartis division.

Onychomycosis is a fungal nail infection primarily caused by dermatophytes.¹ If left untreated, the infection can cause nail destruction and deformities,¹ resulting in pain and discomfort,² impaired foot mobility,³ and an overall reduced quality of life.¹ Onychomycosis is a chronic condition that requires long treatment periods due to the slow growth rates of toenails.¹ To successfully cure the condition, fungal eradication must be achieved.

Prior to the US Food and Drug Administration (FDA) approval of tavaborole and efinaconazole, ciclopirox was the only approved topical treatment for onychomycosis.⁴ The recent approval of tavaborole and efinaconazole has increased treatment options available to patients and has started to pave the way for future topical treatments. This article discusses the 3 approved topical treatments for onychomycosis and focuses on the design of the phase 3 clinical trials that led to their approval.

Topical Agents Used to Treat Onychomycosis

Tavaborole, efinaconazole, and ciclopirox have undergone extensive clinical investigation to receive FDA approval. Results from pivotal phase 3 studies establishing the efficacy and safety of each agent formed the basis for regulatory submission. Although it may seem intuitive to compare the relative performance of these agents based on their respective phase 3 clinical trial data, there are important differences in study methodology, conduct, and populations that prevent direct comparisons. The FDA provides limited guidance to the pharmaceutical industry on how to conduct clinical trials for potential onychomycosis treatments. Comparative efficacy and safety claims are limited based on cross-study comparisons. The details of the phase 3 trial designs are summarized in the Table.

Tavaborole
Tavaborole is a boron-based treatment with a novel mechanism of action.⁵ Tavaborole binds to the editing domain of leucyl–transfer ribonucleic acid synthetase via an integrated boron atom and inhibits fungal protein synthesis.⁶ Two identical randomized, double-blind, vehicle-controlled, parallel-group, phase 3 clinical trials evaluating tavaborole were performed.⁵ The first study (registered at www.clinicaltrials.gov with the identifier NCT01270971) included 594 participants from27 sites in the United States and Mexico and was conducted between December 2010 and November 2012. The second study (NCT01302119) included 604 participants from 32 sites in the United States and Canada and was conducted between February 2011 and January 2013.

Eligible participants 18 years and older had distal subungual onychomycosis (DSO) of the toenails affecting 20% to 60% of 1 or more target great toenails (TGTs), tested positive for fungus using potassium hydroxide (KOH) wet mounts and positive for Trichophyton rubrum and Trichophyton mentagrophytes on fungal culture diagnostic tests, had distal TGT thickness of 3 mm or less, and had 3 mm or more of clear nail between the proximal nail fold and the most proximal visible mycotic border.⁵ Those with active tinea pedis requiring treatment or with a history of chronic moccasin-type tinea pedis were excluded. Participants were randomized to receive either tavaborole or vehicle (2:1). Treatments were applied once daily to all infected toenails for a total of 48 weeks, and nail debridement (defined as partial or complete removal of the toenail) was not permitted. Notably, controlled trimming of the nail was allowed to 1 mm of the leading nail edge. Regular assessments of each toenail for disease involvement, onycholysis, and subungual hyperkeratosis were made at screening, baseline, week 2, week 6, and every 6 weeks thereafter until week 52. Subungual TGT samples were taken at screening and every 12 weeks during the study for examination at a mycology laboratory, which performed KOH and fungal culture tests. A follow-up assessment was made at week 52.⁵

The primary end point was complete cure of the TGT at week 52, with secondary end points of completely or almost clear TGT nail (≤10% dystrophic nail), completely or almost clear TGT nail (≤10% dystrophic nail) plus negative mycology, and negative mycology of TGT.⁵ Examples of TGTs in participants who achieved complete cure and almost clear nails with negative mycology before and after treatment with tavaborole are shown in Figure 1. An example of a patient considered to have treatment failure is shown in Figure 2. This patient showed marked improvement in nail appearance and had a negative culture result but had a positive KOH test, which demonstrates the stringency in which topical agents are judged in onychomycosis trials.⁵

Efinaconazole
Efinaconazole is a topical triazole antifungal specifically indicated to treat onychomycosis. Two identical randomized, vehicle-controlled, double-blind, multicenter trials were performed to assess the safety and efficacy of efinaconazole solution 10%^.7 The first study (NCT01008033) involved 870 participants and was conducted at a total of 74 sites in Japan (33 sites), Canada (7 sites), and the United States (34 sites) between December 2009 and September 2011. The second study (NCT01007708) had 785 participants and was conducted at 44 sites in Canada (8 sites) and the United States (36 sites) between December 2009 and October 2011.

Participants aged 18 to 70 years with a clinical diagnosis of DSO affecting 1 or more TGT were eligible to participate.⁷ Other eligibility criteria included an uninfected toenail length 3 mm or more from the proximal nail fold, a maximum toenail thickness of 3 mm, positive KOH wet mounts, and positive dermatophyte or mixed dermatophyte/candida cultures. Dermatophytes included T rubrum and T mentagrophytes. Those with severe moccasin-type tinea pedis were excluded. Participants were randomized to receive efinaconazole or vehicle (3:1). Once-daily treatments were self-applied to nails for 48 weeks. Clinical assessments were made at baseline and every 12 weeks until week 48, with a follow-up assessment at week 52. No nail trimming protocol was provided.⁷

The primary end point of the efinaconazole phase 3 trials was complete cure at week 52, with secondary end points including mycologic cure, treatment success (≤5% mycotic nail), and complete or almost complete cure (negative culture and KOH, ≤5% mycotic nail). An example of a complete cure from baseline to week 52 is shown in Figure 3.⁷

Ciclopirox
Ciclopirox was the first topical therapy to be approved for the treatment of onychomycosis. Ciclopirox is a broad-spectrum antifungal agent that inhibits metal-dependent enzymes, which are responsible for the degradation of toxic peroxides in fungal cells. The safety and efficacy of ciclopirox nail lacquer topical solution 8% also was investigated in 2 identical phase 3 clinical trials.⁸ The first study was conducted at 9 sites in the United States between June 1994 and June 1996 and included 223 participants. The second study was conducted at 9 sites in the United States between July 1994 and April 1996 and included 237 participants.

Eligible participants were required to have DSO in at least one TGT, positive KOH wet mount with positive dermatophyte culture, and 20% to 65% nail involvement.⁸ Those with tinea pedis were not excluded. Participants were randomized to receive once-daily treatment with ciclopirox or vehicle (1:1)(applied to all toenails and affected fingernails) for 48 weeks. The product was to be removed by the patient with alcohol on a weekly basis. Trimming was allowed as necessary, and mechanical debridement by the physician could be performed monthly. Assessments were made every 4 weeks, and mycologic examinations were performed every 12 weeks. Participants who were clinically cured were assessed further in a 12- to 24-week posttreatment follow-up period.⁸

The primary end point of complete cure and secondary end points of treatment success (negative culture and KOH, ≤10% mycotic nail), mycologic cure, and negative mycologic culture were assessed at week 48.⁸

Phase 3 Clinical Trial Similarities and Differences

The phase 3 clinical trials used to investigate the safety and efficacy of tavaborole,⁵ efinaconazole,⁷ and ciclopirox⁸ were similar in their overall design. All trials were randomized, double-blind, vehicle-controlled studies in patients with DSO. Each agent was assessed using a once-daily application for a treatment period of 48 weeks.

Primary differences among study designs included the age range of participants, the range of mycotic nail involvement, the presence/absence of tinea pedis, and the nail trimming/debridement protocols used. Differences were observed in the patient eligibility criteria of these trials. Both mycotic area and participant age range were inconsistent for each agent (eTable). Participants with larger mycotic areas usually have a poorer prognosis, as they tend to have a greater fungal load.⁹ A baseline mycotic area of 20% to 60%,⁵ 20% to 50%,⁷ and 20% to 65%⁸ at baseline was required for the tavaborole, efinaconazole, and ciclopirox trials, respectively. Variations in mycotic area between trials can affect treatment efficacy, as clinical cures can be reached quicker by patients with smaller areas of infection. Of note, the average mycotic area of involvement was not reported in the tavaborole studies but was 36% and 40% for the efinaconazole and ciclopirox studies, respectively.^5,8 It also is more difficult to achieve complete cure in older patients, as they have poor circulation and reduced nail growth rates.^1,10 The participant age range was 18 to 88 years in the tavaborole trials, with 8% of the participants older than 70 years,⁵ compared to 18 to 71 years in both the efinaconazole and ciclopirox trials.^7,8 The average age of participants in each study was approximately 54, 51, and 50 years for tavaborole, efinaconazole, and ciclopirox, respectively. Because factors impacting treatment failure can increase with age, efficacy results can be confounded by differing age distributions across different studies.

Another important feature that differed between the clinical trials was the approach to nail trimming—defined as shortening of the free edge of the nail distal to the hyponychium—which varies from debridement in that the nail plate is removed or reduced in thickness proximal to the hyponychium. In the tavaborole trials, trimming was controlled to within 1 mm of the free edge of the nail,⁵ whereas the protocol used for the ciclopirox trials allowed nail trimming as necessary as well as moderate debridement before treatment application and on a monthly basis.⁸ Debridement is an important component in all ciclopirox trials, as it is used to reduce fungal load.¹¹ No trimming control was provided during the efinaconazole trials; however, debridement was prohibited.⁷ These differences can dramatically affect the study results, as residual fungal elements and portions of infected nails are removed during the trimming process in an uncontrolled manner, which can affect mycologic testing results as well as the clinical efficacy results determined through investigator evaluation. Discrepancies regarding nail trimming approach inevitably makes the trial results difficult to compare, as mycologic cure is not translatable between studies.

Furthermore, somewhat unusually, complete cure rate variations were observed between different study centers in the efinaconazole trials. Japanese centers in the first efinaconazole study (NCT01008033) had higher complete cure rates in both the efinaconazole and vehicle treatment arms, which is notable because approximately 29% of participants in this study were Asian, mostly hailing from 33 Japanese centers. The reason for these confounding results is unknown and requires further analysis.

Lastly, the presence or absence of tinea pedis can affect the response to onychomycosis treatment. In the tavaborole trials, patients with active interdigital tinea pedis or exclusively plantar tinea pedis or chronic moccasin-type tinea pedis requiring treatment were excluded from the studies.⁵ In contrast, only patients with severe moccasin-type tinea pedis were excluded in efinaconazole trials.⁷ The ciclopirox studies had no exclusions based on presence of tinea pedis.⁸ These differences are noteworthy, as tinea pedis can serve as a reservoir for fungal infection if not treated and can lead to recurrence of onychomycosis.¹²

Conclusion

In recent years, disappointing efficacy has resulted in the failure of several topical agents for onychomycosis during their development; however, there are several aspects to consider when examining efficacy data in onychomycosis studies. Obtaining a complete cure in onychomycosis is difficult. Because patients applying treatments at home are unlikely to undergo mycologic testing to confirm complete cure, visual inspections are helpful to determine treatment efficacy.

Despite similar overall designs, notable differences in the study designs of the phase 3 clinical trials investigating tavaborole, efinaconazole, and ciclopirox are likely to have had an effect on the reported results, making the efficacy of the agents difficult to compare. It is particularly tempting to compare the primary end point results of each trial, especially considering tavaborole and efinaconazole had primary end points with the same parameters; however, there are several other factors (eg, age range of study population, extent of infection, nail trimming, patient demographics) that may have affected the outcomes of the studies and precluded a direct comparison of any end points. Without head-to-head investigations, there is room for prescribing clinicians to interpret results differently.

Acknowledgment

Writing and editorial assistance was provided by ApotheCom Associates, LLC, Yardley, Pennsylvania, and was supported by Sandoz, a Novartis division.

Onychomycosis is a fungal nail infection primarily caused by dermatophytes.¹ If left untreated, the infection can cause nail destruction and deformities,¹ resulting in pain and discomfort,² impaired foot mobility,³ and an overall reduced quality of life.¹ Onychomycosis is a chronic condition that requires long treatment periods due to the slow growth rates of toenails.¹ To successfully cure the condition, fungal eradication must be achieved.

Prior to the US Food and Drug Administration (FDA) approval of tavaborole and efinaconazole, ciclopirox was the only approved topical treatment for onychomycosis.⁴ The recent approval of tavaborole and efinaconazole has increased treatment options available to patients and has started to pave the way for future topical treatments. This article discusses the 3 approved topical treatments for onychomycosis and focuses on the design of the phase 3 clinical trials that led to their approval.

Topical Agents Used to Treat Onychomycosis

Tavaborole, efinaconazole, and ciclopirox have undergone extensive clinical investigation to receive FDA approval. Results from pivotal phase 3 studies establishing the efficacy and safety of each agent formed the basis for regulatory submission. Although it may seem intuitive to compare the relative performance of these agents based on their respective phase 3 clinical trial data, there are important differences in study methodology, conduct, and populations that prevent direct comparisons. The FDA provides limited guidance to the pharmaceutical industry on how to conduct clinical trials for potential onychomycosis treatments. Comparative efficacy and safety claims are limited based on cross-study comparisons. The details of the phase 3 trial designs are summarized in the Table.

Tavaborole
Tavaborole is a boron-based treatment with a novel mechanism of action.⁵ Tavaborole binds to the editing domain of leucyl–transfer ribonucleic acid synthetase via an integrated boron atom and inhibits fungal protein synthesis.⁶ Two identical randomized, double-blind, vehicle-controlled, parallel-group, phase 3 clinical trials evaluating tavaborole were performed.⁵ The first study (registered at www.clinicaltrials.gov with the identifier NCT01270971) included 594 participants from27 sites in the United States and Mexico and was conducted between December 2010 and November 2012. The second study (NCT01302119) included 604 participants from 32 sites in the United States and Canada and was conducted between February 2011 and January 2013.

Eligible participants 18 years and older had distal subungual onychomycosis (DSO) of the toenails affecting 20% to 60% of 1 or more target great toenails (TGTs), tested positive for fungus using potassium hydroxide (KOH) wet mounts and positive for Trichophyton rubrum and Trichophyton mentagrophytes on fungal culture diagnostic tests, had distal TGT thickness of 3 mm or less, and had 3 mm or more of clear nail between the proximal nail fold and the most proximal visible mycotic border.⁵ Those with active tinea pedis requiring treatment or with a history of chronic moccasin-type tinea pedis were excluded. Participants were randomized to receive either tavaborole or vehicle (2:1). Treatments were applied once daily to all infected toenails for a total of 48 weeks, and nail debridement (defined as partial or complete removal of the toenail) was not permitted. Notably, controlled trimming of the nail was allowed to 1 mm of the leading nail edge. Regular assessments of each toenail for disease involvement, onycholysis, and subungual hyperkeratosis were made at screening, baseline, week 2, week 6, and every 6 weeks thereafter until week 52. Subungual TGT samples were taken at screening and every 12 weeks during the study for examination at a mycology laboratory, which performed KOH and fungal culture tests. A follow-up assessment was made at week 52.⁵

The primary end point was complete cure of the TGT at week 52, with secondary end points of completely or almost clear TGT nail (≤10% dystrophic nail), completely or almost clear TGT nail (≤10% dystrophic nail) plus negative mycology, and negative mycology of TGT.⁵ Examples of TGTs in participants who achieved complete cure and almost clear nails with negative mycology before and after treatment with tavaborole are shown in Figure 1. An example of a patient considered to have treatment failure is shown in Figure 2. This patient showed marked improvement in nail appearance and had a negative culture result but had a positive KOH test, which demonstrates the stringency in which topical agents are judged in onychomycosis trials.⁵

Efinaconazole
Efinaconazole is a topical triazole antifungal specifically indicated to treat onychomycosis. Two identical randomized, vehicle-controlled, double-blind, multicenter trials were performed to assess the safety and efficacy of efinaconazole solution 10%^.7 The first study (NCT01008033) involved 870 participants and was conducted at a total of 74 sites in Japan (33 sites), Canada (7 sites), and the United States (34 sites) between December 2009 and September 2011. The second study (NCT01007708) had 785 participants and was conducted at 44 sites in Canada (8 sites) and the United States (36 sites) between December 2009 and October 2011.

Participants aged 18 to 70 years with a clinical diagnosis of DSO affecting 1 or more TGT were eligible to participate.⁷ Other eligibility criteria included an uninfected toenail length 3 mm or more from the proximal nail fold, a maximum toenail thickness of 3 mm, positive KOH wet mounts, and positive dermatophyte or mixed dermatophyte/candida cultures. Dermatophytes included T rubrum and T mentagrophytes. Those with severe moccasin-type tinea pedis were excluded. Participants were randomized to receive efinaconazole or vehicle (3:1). Once-daily treatments were self-applied to nails for 48 weeks. Clinical assessments were made at baseline and every 12 weeks until week 48, with a follow-up assessment at week 52. No nail trimming protocol was provided.⁷

The primary end point of the efinaconazole phase 3 trials was complete cure at week 52, with secondary end points including mycologic cure, treatment success (≤5% mycotic nail), and complete or almost complete cure (negative culture and KOH, ≤5% mycotic nail). An example of a complete cure from baseline to week 52 is shown in Figure 3.⁷

Ciclopirox
Ciclopirox was the first topical therapy to be approved for the treatment of onychomycosis. Ciclopirox is a broad-spectrum antifungal agent that inhibits metal-dependent enzymes, which are responsible for the degradation of toxic peroxides in fungal cells. The safety and efficacy of ciclopirox nail lacquer topical solution 8% also was investigated in 2 identical phase 3 clinical trials.⁸ The first study was conducted at 9 sites in the United States between June 1994 and June 1996 and included 223 participants. The second study was conducted at 9 sites in the United States between July 1994 and April 1996 and included 237 participants.

Eligible participants were required to have DSO in at least one TGT, positive KOH wet mount with positive dermatophyte culture, and 20% to 65% nail involvement.⁸ Those with tinea pedis were not excluded. Participants were randomized to receive once-daily treatment with ciclopirox or vehicle (1:1)(applied to all toenails and affected fingernails) for 48 weeks. The product was to be removed by the patient with alcohol on a weekly basis. Trimming was allowed as necessary, and mechanical debridement by the physician could be performed monthly. Assessments were made every 4 weeks, and mycologic examinations were performed every 12 weeks. Participants who were clinically cured were assessed further in a 12- to 24-week posttreatment follow-up period.⁸

The primary end point of complete cure and secondary end points of treatment success (negative culture and KOH, ≤10% mycotic nail), mycologic cure, and negative mycologic culture were assessed at week 48.⁸

Phase 3 Clinical Trial Similarities and Differences

The phase 3 clinical trials used to investigate the safety and efficacy of tavaborole,⁵ efinaconazole,⁷ and ciclopirox⁸ were similar in their overall design. All trials were randomized, double-blind, vehicle-controlled studies in patients with DSO. Each agent was assessed using a once-daily application for a treatment period of 48 weeks.

Primary differences among study designs included the age range of participants, the range of mycotic nail involvement, the presence/absence of tinea pedis, and the nail trimming/debridement protocols used. Differences were observed in the patient eligibility criteria of these trials. Both mycotic area and participant age range were inconsistent for each agent (eTable). Participants with larger mycotic areas usually have a poorer prognosis, as they tend to have a greater fungal load.⁹ A baseline mycotic area of 20% to 60%,⁵ 20% to 50%,⁷ and 20% to 65%⁸ at baseline was required for the tavaborole, efinaconazole, and ciclopirox trials, respectively. Variations in mycotic area between trials can affect treatment efficacy, as clinical cures can be reached quicker by patients with smaller areas of infection. Of note, the average mycotic area of involvement was not reported in the tavaborole studies but was 36% and 40% for the efinaconazole and ciclopirox studies, respectively.^5,8 It also is more difficult to achieve complete cure in older patients, as they have poor circulation and reduced nail growth rates.^1,10 The participant age range was 18 to 88 years in the tavaborole trials, with 8% of the participants older than 70 years,⁵ compared to 18 to 71 years in both the efinaconazole and ciclopirox trials.^7,8 The average age of participants in each study was approximately 54, 51, and 50 years for tavaborole, efinaconazole, and ciclopirox, respectively. Because factors impacting treatment failure can increase with age, efficacy results can be confounded by differing age distributions across different studies.

Another important feature that differed between the clinical trials was the approach to nail trimming—defined as shortening of the free edge of the nail distal to the hyponychium—which varies from debridement in that the nail plate is removed or reduced in thickness proximal to the hyponychium. In the tavaborole trials, trimming was controlled to within 1 mm of the free edge of the nail,⁵ whereas the protocol used for the ciclopirox trials allowed nail trimming as necessary as well as moderate debridement before treatment application and on a monthly basis.⁸ Debridement is an important component in all ciclopirox trials, as it is used to reduce fungal load.¹¹ No trimming control was provided during the efinaconazole trials; however, debridement was prohibited.⁷ These differences can dramatically affect the study results, as residual fungal elements and portions of infected nails are removed during the trimming process in an uncontrolled manner, which can affect mycologic testing results as well as the clinical efficacy results determined through investigator evaluation. Discrepancies regarding nail trimming approach inevitably makes the trial results difficult to compare, as mycologic cure is not translatable between studies.

Furthermore, somewhat unusually, complete cure rate variations were observed between different study centers in the efinaconazole trials. Japanese centers in the first efinaconazole study (NCT01008033) had higher complete cure rates in both the efinaconazole and vehicle treatment arms, which is notable because approximately 29% of participants in this study were Asian, mostly hailing from 33 Japanese centers. The reason for these confounding results is unknown and requires further analysis.

Lastly, the presence or absence of tinea pedis can affect the response to onychomycosis treatment. In the tavaborole trials, patients with active interdigital tinea pedis or exclusively plantar tinea pedis or chronic moccasin-type tinea pedis requiring treatment were excluded from the studies.⁵ In contrast, only patients with severe moccasin-type tinea pedis were excluded in efinaconazole trials.⁷ The ciclopirox studies had no exclusions based on presence of tinea pedis.⁸ These differences are noteworthy, as tinea pedis can serve as a reservoir for fungal infection if not treated and can lead to recurrence of onychomycosis.¹²

Conclusion

In recent years, disappointing efficacy has resulted in the failure of several topical agents for onychomycosis during their development; however, there are several aspects to consider when examining efficacy data in onychomycosis studies. Obtaining a complete cure in onychomycosis is difficult. Because patients applying treatments at home are unlikely to undergo mycologic testing to confirm complete cure, visual inspections are helpful to determine treatment efficacy.

Despite similar overall designs, notable differences in the study designs of the phase 3 clinical trials investigating tavaborole, efinaconazole, and ciclopirox are likely to have had an effect on the reported results, making the efficacy of the agents difficult to compare. It is particularly tempting to compare the primary end point results of each trial, especially considering tavaborole and efinaconazole had primary end points with the same parameters; however, there are several other factors (eg, age range of study population, extent of infection, nail trimming, patient demographics) that may have affected the outcomes of the studies and precluded a direct comparison of any end points. Without head-to-head investigations, there is room for prescribing clinicians to interpret results differently.

Acknowledgment

Writing and editorial assistance was provided by ApotheCom Associates, LLC, Yardley, Pennsylvania, and was supported by Sandoz, a Novartis division.

Atypical fibroxanthoma (AFX) is a low-grade dermal malignancy comprised of atypical spindle cells.¹ Classified as a superficial fibrohistiocytic tumor with intermediate malignant potential, AFX has an incidence of approximately 0.24% worldwide.² The tumor appears mainly on the head and neck in sun-exposed areas but can occur less frequently on the trunk and limbs in non–sun-exposed areas. There is a 70% to 80% predominance in men aged 69 to 77 years, with lesions primarily occurring in sun-exposed areas of the head and neck.³ A median period of 4 months between time of onset and time of diagnosis has been previously established.⁴

When AFX does occur in non–sun-exposed areas, it tends to be in a younger patient population. Clinically, it presents as a rather nondescript, firm, erythematous papule or nodule less than 2 cm in diameter. Atypical fibroxanthoma most often presents asymptomatically, but the tumor may ulcerate and bleed, though pain and pruritus are uncommon.5 Findings are nonspecific, and the diagnosis must be confirmed with biopsy, as it can resemble other common dermatological lesions. The pathogenesis of AFX has been controversial. Two different studies looked at AFX using electron microscopy and concluded that the tumor most closely resembled a myofibroblast,^6,7 which is consistent with current thinking today.

Atypical fibroxanthoma is believed to be associated with p53 mutation and is closely linked with exposure to UV radiation due to its predominance in sun-exposed areas. Other predisposing factors may include prior exposure to UV radiation, history of organ transplantation, immunosuppression, advanced age in men, and xeroderma pigmentosum. The differential diagnosis for AFX encompasses basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, adnexal tumor, and pyogenic granuloma.

Case Report

A 93-year-old man was referred to our clinic for treatment of erosive pustular dermatosis of the scalp with photodynamic therapy (PDT). He had a more than 20-year history of multiple skin lesions including basal cell carcinoma, squamous cell carcinoma, and actinic keratoses (AKs). For one year prior to the current presentation the patient had concerns of pustules, scaling, itching, and scabbing on the scalp. The patient admitted that the pruritus caused him to pick at the scabs on the scalp. He had previously been treated with lactic acid 12% neutralized with ammonium hydroxide, tacrolimus, and halobetasol, all to no avail.

On physical examination, the lesions appeared erosive with crusting and granulation tissue (Figure 1A). The presentation was consistent with erosive pustular dermatosis of the scalp. Biopsy revealed granulation tissue. The patient underwent PDT and prednisone treatment with improvement. Additional biopsies revealed AKs. His condition improved with 2 PDT sessions but never fully cleared. During the PDT sessions, the patient reported intense unilateral headaches without visual changes. The headaches were intermittent and not apparently related to the treatments. He was referred for a temporal artery biopsy and rebiopsy of the remaining lesion on the scalp. The temporal artery biopsy was negative. The lesion that remained was a large nodule on the vertex scalp, and biopsy revealed AFX.

Immunohistochemical marker studies for S-100 and cytokeratin were negative. Invasion into subcutaneous fat was encountered (Figure 2A). Highly atypical spindle cells and mitoses were present (Figure 2B). Neoplastic cells were noted adjacent to nerve (Figure 2C). Excision of the lesion was curative, and his symptoms of pain and erosive pustular dermatosis resolved weeks thereafter (Figure 1B). The area of erosive pustular dermatosis was not excised, but symptoms resolved weeks following excision of the AFX.

Comment

Our case of AFX is unique due to the patient’s atypical presentation of severe pain. Because AFX usually presents asymptomatically, pain is an uncommon symptom. Based on the histologic findings in our case, we suspected that neural involvement of the tumor most likely explained the intense pain that our patient experienced.

The presence of erosive pustular dermatosis of the scalp also is interesting in our case. This elderly man had an extensive history of actinic damage and had reported pustules, scaling, itching, and scabbing of the scalp. It is possible that erosive pustular dermatosis was superimposed over the tumor and could have been the reason that multiple biopsies were needed to eventually arrive at a diagnosis. The coexistence of the 2 entities suggests that the chronic actinic damage played a role in the etiology of both.

Classification
There is a question regarding nomenclature when discussing AFX. Atypical fibroxanthoma has been referred to as a variant of undifferentiated pleomorphic sarcoma, which is a type of soft tissue sarcoma. Atypical fibroxanthoma can be referred to as undifferentiated pleomorphic sarcoma if it is more than 2 cm in diameter, if it involves the fascia or subcutaneous tissue, or if there is evidence of necrosis.³ Atypical fibroxanthoma generally is confined to the head and neck region and usually is less than 2 cm in diameter. In this patient, the presentation was consistent with AFX, as there was evidence of necrosis and invasion into the subcutaneous fat. The fact that the lesion also appeared on the scalp further supported the diagnosis of AFX.

Pathology
Biopsy of AFX typically reveals a spindle cell proliferation that usually arises in the setting of profound actinic damage. The epidermis may or may not be ulcerated, and in most cases, it is seen in close proximity to the overlying epidermis but not arising from it.8 Classic AFX is composed of highly atypical histiocytelike (epithelioid) cells admixed with pleomorphic spindle cells and giant cells, all showing frequent mitoses including atypical ones.9 Several histologic subtypes of AFX have been described, including clear cell, granular cell, pigmented cell, chondroid, osteoid, osteoclastic, and the most common spindle cell subtype.9 Features that indicate potential aggressive behavior include infiltration into the subcutaneous tissue, vascular invasion, and presence of necrosis. A diagnosis of AFX is made by exclusion of other malignant neoplasms with similar morphology, namely spindle cell squamous cell carcinoma, spindle cell melanoma, and leiomyoscarcoma.9 As such, immunohistochemistry plays a critical role in distinguishing these lesions, as they arise as part of the differential diagnosis. A panel of immunohistochemical stains is helpful for diagnosis and commonly includes but is not limited to S-100, Melan-A, smooth muscle actin, desmin, and cytokeratin.

Sampling error is an inherent flaw in any biopsy specimen. The eventual diagnosis of AFX in our case supports the argument for multiple biopsies of an unknown lesion, seeing as the affected area was interpreted as both granulation tissue and AK prior to the eventual diagnosis. Repeat biopsies, especially if a lesion is nonhealing, often can help clinicians arrive at a definitive diagnosis.

Treatment
Different treatment options have been used to manage AFX. Mohs micrographic surgery is most often used because of its tissue-sparing potential, often giving the most cosmetically appealing result. Wide local excision is another surgical technique utilized, generally with fixed margins of at least 1 cm.¹⁰ Radiation at the tumor site is used as a treatment method but most often during cases of reoccurrence. Cryotherapy as well as electrodesiccation and curettage are possible treatment options but are not the standard of care.

Atypical fibroxanthoma (AFX) is a low-grade dermal malignancy comprised of atypical spindle cells.¹ Classified as a superficial fibrohistiocytic tumor with intermediate malignant potential, AFX has an incidence of approximately 0.24% worldwide.² The tumor appears mainly on the head and neck in sun-exposed areas but can occur less frequently on the trunk and limbs in non–sun-exposed areas. There is a 70% to 80% predominance in men aged 69 to 77 years, with lesions primarily occurring in sun-exposed areas of the head and neck.³ A median period of 4 months between time of onset and time of diagnosis has been previously established.⁴

When AFX does occur in non–sun-exposed areas, it tends to be in a younger patient population. Clinically, it presents as a rather nondescript, firm, erythematous papule or nodule less than 2 cm in diameter. Atypical fibroxanthoma most often presents asymptomatically, but the tumor may ulcerate and bleed, though pain and pruritus are uncommon.5 Findings are nonspecific, and the diagnosis must be confirmed with biopsy, as it can resemble other common dermatological lesions. The pathogenesis of AFX has been controversial. Two different studies looked at AFX using electron microscopy and concluded that the tumor most closely resembled a myofibroblast,^6,7 which is consistent with current thinking today.

Atypical fibroxanthoma is believed to be associated with p53 mutation and is closely linked with exposure to UV radiation due to its predominance in sun-exposed areas. Other predisposing factors may include prior exposure to UV radiation, history of organ transplantation, immunosuppression, advanced age in men, and xeroderma pigmentosum. The differential diagnosis for AFX encompasses basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, adnexal tumor, and pyogenic granuloma.

Case Report

A 93-year-old man was referred to our clinic for treatment of erosive pustular dermatosis of the scalp with photodynamic therapy (PDT). He had a more than 20-year history of multiple skin lesions including basal cell carcinoma, squamous cell carcinoma, and actinic keratoses (AKs). For one year prior to the current presentation the patient had concerns of pustules, scaling, itching, and scabbing on the scalp. The patient admitted that the pruritus caused him to pick at the scabs on the scalp. He had previously been treated with lactic acid 12% neutralized with ammonium hydroxide, tacrolimus, and halobetasol, all to no avail.

On physical examination, the lesions appeared erosive with crusting and granulation tissue (Figure 1A). The presentation was consistent with erosive pustular dermatosis of the scalp. Biopsy revealed granulation tissue. The patient underwent PDT and prednisone treatment with improvement. Additional biopsies revealed AKs. His condition improved with 2 PDT sessions but never fully cleared. During the PDT sessions, the patient reported intense unilateral headaches without visual changes. The headaches were intermittent and not apparently related to the treatments. He was referred for a temporal artery biopsy and rebiopsy of the remaining lesion on the scalp. The temporal artery biopsy was negative. The lesion that remained was a large nodule on the vertex scalp, and biopsy revealed AFX.

Immunohistochemical marker studies for S-100 and cytokeratin were negative. Invasion into subcutaneous fat was encountered (Figure 2A). Highly atypical spindle cells and mitoses were present (Figure 2B). Neoplastic cells were noted adjacent to nerve (Figure 2C). Excision of the lesion was curative, and his symptoms of pain and erosive pustular dermatosis resolved weeks thereafter (Figure 1B). The area of erosive pustular dermatosis was not excised, but symptoms resolved weeks following excision of the AFX.

Comment

Our case of AFX is unique due to the patient’s atypical presentation of severe pain. Because AFX usually presents asymptomatically, pain is an uncommon symptom. Based on the histologic findings in our case, we suspected that neural involvement of the tumor most likely explained the intense pain that our patient experienced.

The presence of erosive pustular dermatosis of the scalp also is interesting in our case. This elderly man had an extensive history of actinic damage and had reported pustules, scaling, itching, and scabbing of the scalp. It is possible that erosive pustular dermatosis was superimposed over the tumor and could have been the reason that multiple biopsies were needed to eventually arrive at a diagnosis. The coexistence of the 2 entities suggests that the chronic actinic damage played a role in the etiology of both.

Classification
There is a question regarding nomenclature when discussing AFX. Atypical fibroxanthoma has been referred to as a variant of undifferentiated pleomorphic sarcoma, which is a type of soft tissue sarcoma. Atypical fibroxanthoma can be referred to as undifferentiated pleomorphic sarcoma if it is more than 2 cm in diameter, if it involves the fascia or subcutaneous tissue, or if there is evidence of necrosis.³ Atypical fibroxanthoma generally is confined to the head and neck region and usually is less than 2 cm in diameter. In this patient, the presentation was consistent with AFX, as there was evidence of necrosis and invasion into the subcutaneous fat. The fact that the lesion also appeared on the scalp further supported the diagnosis of AFX.

Pathology
Biopsy of AFX typically reveals a spindle cell proliferation that usually arises in the setting of profound actinic damage. The epidermis may or may not be ulcerated, and in most cases, it is seen in close proximity to the overlying epidermis but not arising from it.8 Classic AFX is composed of highly atypical histiocytelike (epithelioid) cells admixed with pleomorphic spindle cells and giant cells, all showing frequent mitoses including atypical ones.9 Several histologic subtypes of AFX have been described, including clear cell, granular cell, pigmented cell, chondroid, osteoid, osteoclastic, and the most common spindle cell subtype.9 Features that indicate potential aggressive behavior include infiltration into the subcutaneous tissue, vascular invasion, and presence of necrosis. A diagnosis of AFX is made by exclusion of other malignant neoplasms with similar morphology, namely spindle cell squamous cell carcinoma, spindle cell melanoma, and leiomyoscarcoma.9 As such, immunohistochemistry plays a critical role in distinguishing these lesions, as they arise as part of the differential diagnosis. A panel of immunohistochemical stains is helpful for diagnosis and commonly includes but is not limited to S-100, Melan-A, smooth muscle actin, desmin, and cytokeratin.

Sampling error is an inherent flaw in any biopsy specimen. The eventual diagnosis of AFX in our case supports the argument for multiple biopsies of an unknown lesion, seeing as the affected area was interpreted as both granulation tissue and AK prior to the eventual diagnosis. Repeat biopsies, especially if a lesion is nonhealing, often can help clinicians arrive at a definitive diagnosis.

Treatment
Different treatment options have been used to manage AFX. Mohs micrographic surgery is most often used because of its tissue-sparing potential, often giving the most cosmetically appealing result. Wide local excision is another surgical technique utilized, generally with fixed margins of at least 1 cm.¹⁰ Radiation at the tumor site is used as a treatment method but most often during cases of reoccurrence. Cryotherapy as well as electrodesiccation and curettage are possible treatment options but are not the standard of care.

Atypical fibroxanthoma (AFX) is a low-grade dermal malignancy comprised of atypical spindle cells.¹ Classified as a superficial fibrohistiocytic tumor with intermediate malignant potential, AFX has an incidence of approximately 0.24% worldwide.² The tumor appears mainly on the head and neck in sun-exposed areas but can occur less frequently on the trunk and limbs in non–sun-exposed areas. There is a 70% to 80% predominance in men aged 69 to 77 years, with lesions primarily occurring in sun-exposed areas of the head and neck.³ A median period of 4 months between time of onset and time of diagnosis has been previously established.⁴

When AFX does occur in non–sun-exposed areas, it tends to be in a younger patient population. Clinically, it presents as a rather nondescript, firm, erythematous papule or nodule less than 2 cm in diameter. Atypical fibroxanthoma most often presents asymptomatically, but the tumor may ulcerate and bleed, though pain and pruritus are uncommon.5 Findings are nonspecific, and the diagnosis must be confirmed with biopsy, as it can resemble other common dermatological lesions. The pathogenesis of AFX has been controversial. Two different studies looked at AFX using electron microscopy and concluded that the tumor most closely resembled a myofibroblast,^6,7 which is consistent with current thinking today.

Atypical fibroxanthoma is believed to be associated with p53 mutation and is closely linked with exposure to UV radiation due to its predominance in sun-exposed areas. Other predisposing factors may include prior exposure to UV radiation, history of organ transplantation, immunosuppression, advanced age in men, and xeroderma pigmentosum. The differential diagnosis for AFX encompasses basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, adnexal tumor, and pyogenic granuloma.

Case Report

A 93-year-old man was referred to our clinic for treatment of erosive pustular dermatosis of the scalp with photodynamic therapy (PDT). He had a more than 20-year history of multiple skin lesions including basal cell carcinoma, squamous cell carcinoma, and actinic keratoses (AKs). For one year prior to the current presentation the patient had concerns of pustules, scaling, itching, and scabbing on the scalp. The patient admitted that the pruritus caused him to pick at the scabs on the scalp. He had previously been treated with lactic acid 12% neutralized with ammonium hydroxide, tacrolimus, and halobetasol, all to no avail.

On physical examination, the lesions appeared erosive with crusting and granulation tissue (Figure 1A). The presentation was consistent with erosive pustular dermatosis of the scalp. Biopsy revealed granulation tissue. The patient underwent PDT and prednisone treatment with improvement. Additional biopsies revealed AKs. His condition improved with 2 PDT sessions but never fully cleared. During the PDT sessions, the patient reported intense unilateral headaches without visual changes. The headaches were intermittent and not apparently related to the treatments. He was referred for a temporal artery biopsy and rebiopsy of the remaining lesion on the scalp. The temporal artery biopsy was negative. The lesion that remained was a large nodule on the vertex scalp, and biopsy revealed AFX.

Immunohistochemical marker studies for S-100 and cytokeratin were negative. Invasion into subcutaneous fat was encountered (Figure 2A). Highly atypical spindle cells and mitoses were present (Figure 2B). Neoplastic cells were noted adjacent to nerve (Figure 2C). Excision of the lesion was curative, and his symptoms of pain and erosive pustular dermatosis resolved weeks thereafter (Figure 1B). The area of erosive pustular dermatosis was not excised, but symptoms resolved weeks following excision of the AFX.

Comment

Our case of AFX is unique due to the patient’s atypical presentation of severe pain. Because AFX usually presents asymptomatically, pain is an uncommon symptom. Based on the histologic findings in our case, we suspected that neural involvement of the tumor most likely explained the intense pain that our patient experienced.

The presence of erosive pustular dermatosis of the scalp also is interesting in our case. This elderly man had an extensive history of actinic damage and had reported pustules, scaling, itching, and scabbing of the scalp. It is possible that erosive pustular dermatosis was superimposed over the tumor and could have been the reason that multiple biopsies were needed to eventually arrive at a diagnosis. The coexistence of the 2 entities suggests that the chronic actinic damage played a role in the etiology of both.

Classification
There is a question regarding nomenclature when discussing AFX. Atypical fibroxanthoma has been referred to as a variant of undifferentiated pleomorphic sarcoma, which is a type of soft tissue sarcoma. Atypical fibroxanthoma can be referred to as undifferentiated pleomorphic sarcoma if it is more than 2 cm in diameter, if it involves the fascia or subcutaneous tissue, or if there is evidence of necrosis.³ Atypical fibroxanthoma generally is confined to the head and neck region and usually is less than 2 cm in diameter. In this patient, the presentation was consistent with AFX, as there was evidence of necrosis and invasion into the subcutaneous fat. The fact that the lesion also appeared on the scalp further supported the diagnosis of AFX.

Pathology
Biopsy of AFX typically reveals a spindle cell proliferation that usually arises in the setting of profound actinic damage. The epidermis may or may not be ulcerated, and in most cases, it is seen in close proximity to the overlying epidermis but not arising from it.8 Classic AFX is composed of highly atypical histiocytelike (epithelioid) cells admixed with pleomorphic spindle cells and giant cells, all showing frequent mitoses including atypical ones.9 Several histologic subtypes of AFX have been described, including clear cell, granular cell, pigmented cell, chondroid, osteoid, osteoclastic, and the most common spindle cell subtype.9 Features that indicate potential aggressive behavior include infiltration into the subcutaneous tissue, vascular invasion, and presence of necrosis. A diagnosis of AFX is made by exclusion of other malignant neoplasms with similar morphology, namely spindle cell squamous cell carcinoma, spindle cell melanoma, and leiomyoscarcoma.9 As such, immunohistochemistry plays a critical role in distinguishing these lesions, as they arise as part of the differential diagnosis. A panel of immunohistochemical stains is helpful for diagnosis and commonly includes but is not limited to S-100, Melan-A, smooth muscle actin, desmin, and cytokeratin.

Sampling error is an inherent flaw in any biopsy specimen. The eventual diagnosis of AFX in our case supports the argument for multiple biopsies of an unknown lesion, seeing as the affected area was interpreted as both granulation tissue and AK prior to the eventual diagnosis. Repeat biopsies, especially if a lesion is nonhealing, often can help clinicians arrive at a definitive diagnosis.

Treatment
Different treatment options have been used to manage AFX. Mohs micrographic surgery is most often used because of its tissue-sparing potential, often giving the most cosmetically appealing result. Wide local excision is another surgical technique utilized, generally with fixed margins of at least 1 cm.¹⁰ Radiation at the tumor site is used as a treatment method but most often during cases of reoccurrence. Cryotherapy as well as electrodesiccation and curettage are possible treatment options but are not the standard of care.

SAN DIEGO – There is currently no standard protocol for injecting autologous platelet-rich plasma to stimulate hair growth, but the technique appears to be about 50% effective, according to Marc R. Avram, MD.

“I tell patients that this is not FDA [Food and Drug Administration] approved, but we think it to be safe,” said Dr. Avram, clinical professor of dermatology at the Cornell University, New York, said at the annual Masters of Aesthetics Symposium. “We don’t know how well it’s going to work. There are a lot of published data on it, but none of [them are] randomized or controlled long-term.”

toeytoey2530/Thinkstock

[email protected]

SAN DIEGO – There is currently no standard protocol for injecting autologous platelet-rich plasma to stimulate hair growth, but the technique appears to be about 50% effective, according to Marc R. Avram, MD.

“I tell patients that this is not FDA [Food and Drug Administration] approved, but we think it to be safe,” said Dr. Avram, clinical professor of dermatology at the Cornell University, New York, said at the annual Masters of Aesthetics Symposium. “We don’t know how well it’s going to work. There are a lot of published data on it, but none of [them are] randomized or controlled long-term.”

toeytoey2530/Thinkstock

[email protected]

SAN DIEGO – There is currently no standard protocol for injecting autologous platelet-rich plasma to stimulate hair growth, but the technique appears to be about 50% effective, according to Marc R. Avram, MD.

“I tell patients that this is not FDA [Food and Drug Administration] approved, but we think it to be safe,” said Dr. Avram, clinical professor of dermatology at the Cornell University, New York, said at the annual Masters of Aesthetics Symposium. “We don’t know how well it’s going to work. There are a lot of published data on it, but none of [them are] randomized or controlled long-term.”

toeytoey2530/Thinkstock

[email protected]

SILVER SPRING, MD. – Alopecia areata patients struggle as much, if not more so, with the social and emotional challenges of the disease as with the physical challenges, according to patients and others who spoke at a public meeting on alopecia areata patient-focused drug development.

Alopecia areata affects as many as 6.8 million individuals in the United States, according to the National Alopecia Areata Foundation (NAAF). However, the particulars of alopecia can vary widely from one person to another; some patients experience total hair loss (alopecia universalis), while others retain eyebrows, eyelashes, or some body hair.

The FDA meeting, held on Sept. 11, is part of the agency’s patient-focused drug development initiative. “We wanted to hear the broader patient’s voice,” Theresa M. Mullin, PhD, director of the FDA’s Office of Strategic Programs, said in her opening remarks. Gary Sherwood, communications director for NAAF, said that the meeting was the culmination of a 5-year effort, begun in 2012 when alopecia areata was named as one of 39 disease categories under consideration for such a meeting. “It is too early to know what the exact results will be … but if the past is any indication, they may be significant. The meeting held with psoriasis yielded FDA approval of a treatment previously denied,” he added in an interview.

Two panel presentations featured patients who discussed their experiences with alopecia; each was followed by a discussion period where patients and family members in the audience were invited to share their experiences.

The “Health Effects and Daily Impacts” panel allowed several patients and their family members the opportunity to identify specific issues that may surprise clinicians.

Heidi Splete/Frontline Medical News

SILVER SPRING, MD. – Alopecia areata patients struggle as much, if not more so, with the social and emotional challenges of the disease as with the physical challenges, according to patients and others who spoke at a public meeting on alopecia areata patient-focused drug development.

Alopecia areata affects as many as 6.8 million individuals in the United States, according to the National Alopecia Areata Foundation (NAAF). However, the particulars of alopecia can vary widely from one person to another; some patients experience total hair loss (alopecia universalis), while others retain eyebrows, eyelashes, or some body hair.

The FDA meeting, held on Sept. 11, is part of the agency’s patient-focused drug development initiative. “We wanted to hear the broader patient’s voice,” Theresa M. Mullin, PhD, director of the FDA’s Office of Strategic Programs, said in her opening remarks. Gary Sherwood, communications director for NAAF, said that the meeting was the culmination of a 5-year effort, begun in 2012 when alopecia areata was named as one of 39 disease categories under consideration for such a meeting. “It is too early to know what the exact results will be … but if the past is any indication, they may be significant. The meeting held with psoriasis yielded FDA approval of a treatment previously denied,” he added in an interview.

Two panel presentations featured patients who discussed their experiences with alopecia; each was followed by a discussion period where patients and family members in the audience were invited to share their experiences.

The “Health Effects and Daily Impacts” panel allowed several patients and their family members the opportunity to identify specific issues that may surprise clinicians.

Heidi Splete/Frontline Medical News

SILVER SPRING, MD. – Alopecia areata patients struggle as much, if not more so, with the social and emotional challenges of the disease as with the physical challenges, according to patients and others who spoke at a public meeting on alopecia areata patient-focused drug development.

Alopecia areata affects as many as 6.8 million individuals in the United States, according to the National Alopecia Areata Foundation (NAAF). However, the particulars of alopecia can vary widely from one person to another; some patients experience total hair loss (alopecia universalis), while others retain eyebrows, eyelashes, or some body hair.

The FDA meeting, held on Sept. 11, is part of the agency’s patient-focused drug development initiative. “We wanted to hear the broader patient’s voice,” Theresa M. Mullin, PhD, director of the FDA’s Office of Strategic Programs, said in her opening remarks. Gary Sherwood, communications director for NAAF, said that the meeting was the culmination of a 5-year effort, begun in 2012 when alopecia areata was named as one of 39 disease categories under consideration for such a meeting. “It is too early to know what the exact results will be … but if the past is any indication, they may be significant. The meeting held with psoriasis yielded FDA approval of a treatment previously denied,” he added in an interview.

Two panel presentations featured patients who discussed their experiences with alopecia; each was followed by a discussion period where patients and family members in the audience were invited to share their experiences.

The “Health Effects and Daily Impacts” panel allowed several patients and their family members the opportunity to identify specific issues that may surprise clinicians.

Heidi Splete/Frontline Medical News

SILVER SPRING, MD. – The emotional challenges facing alopecia areata patients are as tough, or tougher, than the physical challenges, according to many patients participating in a public meeting on alopecia areata patient-focused drug development.

A panel of patients shared their experiences of living with alopecia areata, including Elizabeth DeCarlo of Wilmington, Delaware. In a video interview at the meeting, held at FDA headquarters on Sept. 11, Ms. DeCarlo elaborated on what she would like clinicians to understand about alopecia patients that might surprise them, and what matters to her as a patient.

“I would tell them to be more compassionate,” Ms. DeCarlo said. “It’s very emotional.” She also emphasized the value of giving alopecia patients information about local support groups, as well as national organizations such as the National Alopecia Areata Foundation.

Ms. DeCarlo had no financial conflicts to disclose.

SILVER SPRING, MD. – The emotional challenges facing alopecia areata patients are as tough, or tougher, than the physical challenges, according to many patients participating in a public meeting on alopecia areata patient-focused drug development.

A panel of patients shared their experiences of living with alopecia areata, including Elizabeth DeCarlo of Wilmington, Delaware. In a video interview at the meeting, held at FDA headquarters on Sept. 11, Ms. DeCarlo elaborated on what she would like clinicians to understand about alopecia patients that might surprise them, and what matters to her as a patient.

“I would tell them to be more compassionate,” Ms. DeCarlo said. “It’s very emotional.” She also emphasized the value of giving alopecia patients information about local support groups, as well as national organizations such as the National Alopecia Areata Foundation.

Ms. DeCarlo had no financial conflicts to disclose.

SILVER SPRING, MD. – The emotional challenges facing alopecia areata patients are as tough, or tougher, than the physical challenges, according to many patients participating in a public meeting on alopecia areata patient-focused drug development.

A panel of patients shared their experiences of living with alopecia areata, including Elizabeth DeCarlo of Wilmington, Delaware. In a video interview at the meeting, held at FDA headquarters on Sept. 11, Ms. DeCarlo elaborated on what she would like clinicians to understand about alopecia patients that might surprise them, and what matters to her as a patient.

“I would tell them to be more compassionate,” Ms. DeCarlo said. “It’s very emotional.” She also emphasized the value of giving alopecia patients information about local support groups, as well as national organizations such as the National Alopecia Areata Foundation.

Ms. DeCarlo had no financial conflicts to disclose.

REPORTING FROM MOAS 2017

SAN DIEGO – Hair removal ranks as the most popular laser procedure performed in the United States, but patients with blond, red, or gray hairs are out of luck, since those threadlike strands lack a chromophore for the laser to respond to.

“For now, I recommend that these patients get electrolysis or use eflornithine cream,” Arisa Ortiz, MD, said at the annual Masters of Aesthetics Symposium.

Future treatment options for patients with light-colored hair look promising, however. One emerging technology combines laser hair removal with the insertion of a silver nanoparticle into the unpigmented hair follicle. “These are currently in pivotal trials, so we should be seeing them on the market very soon,” she said.

According to Dr. Ortiz, director of laser and cosmetic dermatology in the department of dermatology at the University of California, San Diego, there is still a place for nonlaser hair removal, including shaving, waxing, threading, and electrolysis, but laser hair removal is safe, effective in skilled hands, and permanent. Key factors in optimizing treatment include understanding laser safety and laser-tissue interaction, proper patient selection, preoperative preparation, parameter selection, and recognizing complications.

REPORTING FROM MOAS 2017

SAN DIEGO – Hair removal ranks as the most popular laser procedure performed in the United States, but patients with blond, red, or gray hairs are out of luck, since those threadlike strands lack a chromophore for the laser to respond to.

“For now, I recommend that these patients get electrolysis or use eflornithine cream,” Arisa Ortiz, MD, said at the annual Masters of Aesthetics Symposium.

Future treatment options for patients with light-colored hair look promising, however. One emerging technology combines laser hair removal with the insertion of a silver nanoparticle into the unpigmented hair follicle. “These are currently in pivotal trials, so we should be seeing them on the market very soon,” she said.

According to Dr. Ortiz, director of laser and cosmetic dermatology in the department of dermatology at the University of California, San Diego, there is still a place for nonlaser hair removal, including shaving, waxing, threading, and electrolysis, but laser hair removal is safe, effective in skilled hands, and permanent. Key factors in optimizing treatment include understanding laser safety and laser-tissue interaction, proper patient selection, preoperative preparation, parameter selection, and recognizing complications.

REPORTING FROM MOAS 2017

SAN DIEGO – Hair removal ranks as the most popular laser procedure performed in the United States, but patients with blond, red, or gray hairs are out of luck, since those threadlike strands lack a chromophore for the laser to respond to.

“For now, I recommend that these patients get electrolysis or use eflornithine cream,” Arisa Ortiz, MD, said at the annual Masters of Aesthetics Symposium.

Future treatment options for patients with light-colored hair look promising, however. One emerging technology combines laser hair removal with the insertion of a silver nanoparticle into the unpigmented hair follicle. “These are currently in pivotal trials, so we should be seeing them on the market very soon,” she said.

According to Dr. Ortiz, director of laser and cosmetic dermatology in the department of dermatology at the University of California, San Diego, there is still a place for nonlaser hair removal, including shaving, waxing, threading, and electrolysis, but laser hair removal is safe, effective in skilled hands, and permanent. Key factors in optimizing treatment include understanding laser safety and laser-tissue interaction, proper patient selection, preoperative preparation, parameter selection, and recognizing complications.