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Deep dermatophytosis in immunocompromised patients is distinct from Majocchi’s granuloma

July 17 2017

Dermatophytes usually inhabit keratinised tissue and hardly affect the dermis. Deep dermatophytosis in the dermis has recently been described, without invasion through the hair follicle, by Ruben Kershenovich and colleagues from Petach Tikva, Israel.

In immunocompromised patients Trichophyton species are able to invade the dermis by invading through hair follicles. Granulomas in the periphery of hair follicles produce abscesses in the centre which become encapsulated by fibrous capsules and form cysts. This unusual presentation was first described in 1883, Domenico Majocchi (1849-1929), which he termed granuloma tricofitico. It is usually caused by Trichophyton rubrum and may develop in any hair-bearing skin, commonly on the face and the extremities. The fungus is seen entering through the hair follicles into the dermis.

Deep dermatophytosis not involving invasion through the hair follicle into the dermis is distinct. Kershenovich and colleagues describe a case series of deep dermatophytosis in immunosuppressed patients, usually transplantation. The experience of a tertiary dermato-mycology clinic in Israel is presented. Ten patients were identified: nine after solid-organ transplantation and one undergoing chemotherapy, all diagnosed within three-years after beginning immunosuppression (average 7.5 months). The infective agent in nine cases was Trichophyton rubrum. Of particular interest was that all patients presented with concurrent superficial fungal infection suggesting that the focus of dermatophyte growth within the stratum corneum was a reservoir for growth through the basement zone of the skin into the dermis. The feature that differentiates these patients from those with Majocchi’s granuloma is that there was no histological evidence of hair-follicle involvement. This case series suggests that deep dermatophytosis is a separate entity, clinically and histopathologically distinct from Marjocchi’s granuloma.

Deep dermatophytosis occurs only in immunocompromised patients and is characterized by discrete nodules, an indolent course, the absence of follicular invasion and occurs in proximity to a superficial dermatophytes infection. Systemic antifungal treatment leads to complete resolution if started in a timely manner. Chronic mucocutaneous infections are generally the result of primary or secondary immune dysfunction. Patients with autosomal recessive CARD9 mutations are also predisposed to recurrent mucocutaneous and invasive fungal infections with Candida spp., dermatophytes (for example, Trichophyton spp.) and phaeohyphomycetes (Exophiala spp., Phialophora verrucosa).