Location
Philadelphia, PA
Start Date
17-4-2026 1:30 PM
End Date
17-4-2026 2:30 PM
Description
Background: Tricophyton indotineae is a dermatophyte endemic to South Asia that has been increasingly prevalent in the United States. Its atypical appearance and resemblance to atopic dermatitis (AD), clinically and histologically, has resulted in misdiagnosis and mismanagement. It is associated with multidrug resistance which complicates treatment when mismanaged. It is associated with multidrug resistance which complicates treatment when mismanaged. Unlike classic tinea with annular lesions and central clearing, T. indotineae often presents as chronic, diffuse, pruritic, scaly, erythematous plaques involving the groin, buttocks, trunk, and face.
Case Presentation: We were presented with two cases of chronic T. indotineae infections that were being treated as adult-onset AD with topical steroids and immune modulators without resolution. A punch biopsy and fungal culture confirmed T. indotineae and antifungal therapy was initiated.
Discussion: The clinical similarity between AD and T.indotineae can lead to mistreatment, a prolonged infection course with the potential to spread, and hardship on the patient. AD in adulthood is less common and often a diagnosis of exclusion. To be thorough in a treatment-resistant eczematous profile, a skin biopsy, targeted laboratory tests, microscopic examination, and a KOH preparation may be indicated. Additionally, social history including travel to endemic areas is important. These measures may decrease mistreatment as AD treatments are ineffective for T. indotineae infections often make it worse.
Conclusion: T. indotineae represents an emerging global dermatophyte that may masquerade as adult-onset atopic dermatitis, particularly in patients with travel history to South Asia. As illustrated in these two cases, mismanagement not only delays clearance but may exacerbate the infection through immunosuppression and promote antifungal resistance, especially to terbinafine. Clinicians should maintain a high index of suspicion for T. indotineae in any presumed adult-onset or refractory AD that lacks personal or family history of atopy, involves atypical sites (buttocks and groin), or fails to improve after adequate trials of standard AD therapies. Early performance of a punch biopsy combined with fungal
culture is the gold standard for diagnosis. Simple bedside KOH preparation can be helpful but may also be falsely negative, especially in steroid-treated skin. Given the high prevalence of terbinafine resistance in T. indotineae isolates, itraconazole or voriconazole should be considered first-line systemic therapy. These cases underscore the importance of global awareness of evolving dermatophyte epidemiology in an era of frequent travel and migration.
Embargo Period
6-4-2026
Included in
Chronic Trichophyton indotineae Infections Mimicking Adult-Onset Atopic Dermatitis
Philadelphia, PA
Background: Tricophyton indotineae is a dermatophyte endemic to South Asia that has been increasingly prevalent in the United States. Its atypical appearance and resemblance to atopic dermatitis (AD), clinically and histologically, has resulted in misdiagnosis and mismanagement. It is associated with multidrug resistance which complicates treatment when mismanaged. It is associated with multidrug resistance which complicates treatment when mismanaged. Unlike classic tinea with annular lesions and central clearing, T. indotineae often presents as chronic, diffuse, pruritic, scaly, erythematous plaques involving the groin, buttocks, trunk, and face.
Case Presentation: We were presented with two cases of chronic T. indotineae infections that were being treated as adult-onset AD with topical steroids and immune modulators without resolution. A punch biopsy and fungal culture confirmed T. indotineae and antifungal therapy was initiated.
Discussion: The clinical similarity between AD and T.indotineae can lead to mistreatment, a prolonged infection course with the potential to spread, and hardship on the patient. AD in adulthood is less common and often a diagnosis of exclusion. To be thorough in a treatment-resistant eczematous profile, a skin biopsy, targeted laboratory tests, microscopic examination, and a KOH preparation may be indicated. Additionally, social history including travel to endemic areas is important. These measures may decrease mistreatment as AD treatments are ineffective for T. indotineae infections often make it worse.
Conclusion: T. indotineae represents an emerging global dermatophyte that may masquerade as adult-onset atopic dermatitis, particularly in patients with travel history to South Asia. As illustrated in these two cases, mismanagement not only delays clearance but may exacerbate the infection through immunosuppression and promote antifungal resistance, especially to terbinafine. Clinicians should maintain a high index of suspicion for T. indotineae in any presumed adult-onset or refractory AD that lacks personal or family history of atopy, involves atypical sites (buttocks and groin), or fails to improve after adequate trials of standard AD therapies. Early performance of a punch biopsy combined with fungal
culture is the gold standard for diagnosis. Simple bedside KOH preparation can be helpful but may also be falsely negative, especially in steroid-treated skin. Given the high prevalence of terbinafine resistance in T. indotineae isolates, itraconazole or voriconazole should be considered first-line systemic therapy. These cases underscore the importance of global awareness of evolving dermatophyte epidemiology in an era of frequent travel and migration.