A new mutation in the SQLE gene of Trichophyton mentagrophytes associated to terbinafine resistance in a couple with disseminated tinea corporis.

Trichophyton is the most common dermatophyte genus responsible for tinea corporis and topical treatment with terbinafine is effective for limited disease but extensive disease required systemic therapy. Failure of terbinafine therapy in patients infected with T. rubrum or T. mentagrophytes is associated with mutations in the gene encoding squalene epoxidase, the terbinafine target. We report two cases of tinea corporis resistant to systemic terbinafine in a 60-year-old man and his wife, a 51 year-old-woman. Both patients had multiple diffuse erythematous annular scaly plaques and T. mentagrophytes was isolated in culture. Systemic treatment with terbinafine in combination with topical terbinafine and then topical ketoconazole failed to improve the disease after 8 weeks. The broth microdilution tests performed to evaluate the antifungal sensitivity of the T. mentagrophytes isolate revealed a high MIC for terbinafine but a low MIC for posaconazole and itraconazole. An A1223T point mutation leading to a Q408L substitution was identified by DNA sequencing the SQLE gene of the isolate. Itraconazole 200mg daily was then introduced but stopped because of elevated liver transaminases in the man. Finally, complete healing was achieved only six months later for both patients and required a 3 and 2-week regimen of itraconazole with topical eberconazole in the man and woman respectively. We believe that a close monitoring and antifungal susceptibility tests should now be done more systematically in dermatophytic infections that do not respond to conventional treatment as terbinafine resistant strains are likely to spread worlwide.

[Pityriasis rubra pilaris]. / Pityriasis rubra pilaire.

Pityriasis rubra pilaris is a rare heterogeneous dermatosis associating three clinical signs to different degrees: follicular corneal papules, reddish-orange palmoplantar keratoderma and erythematosquamous lesions that may in some cases be very extensive, interspersed with patches of healthy skin. The aetiology is unclear, and in most cases, the trigger factors consist of trauma or infection, probably in subjects with an existing predisposition. In other cases, the condition is associated with immunological disorders or, in familial cases, genetic keratinisation abnormalities similar to ichthyosis. Given the widely varying signs, several classifications have been proposed, based on clinical criteria and outcomes. The outcome varies in accordance with the clinical forms involved. Therapeutic approaches are poorly qualified and there have been no clinical trials due to the rarity of the disease. However, the best results appear to have been obtained using oral retinoids, with second-line therapy comprising methotrexate and cyclosporine. The landscape of therapeutic strategy seems to be changing with the advent of new anti-tumour necrosis factor and anti-interleukin-12/23 antibodies.

Pruritic acquired nevus of Ota.

Nevus of Ota is a unilateral, asymptomatic cutaneous and mucosal hyperpigmentation of the face that is congenital or may appear during childhood. We present a case of symptomatic acquired nevus of Ota in an adult, associated with intense pruritus, not described in the literature so far. A 32-year-old woman presented with brownish mottled macules which appeared on her face progressively over 8 days, following the distribution of the first and second divisions of the left trigeminal nerve and partially covering the iris and sclera of the left eye. She reported an intense pruritus in this area. We performed a biopsy on the left forehead, which confirmed the diagnosis of nevus of Ota. Specific stains and immunohistochemistry revealed increased numbers of mast cells. Ophthalmological tests showed acute acquired melanocytosis of the left iris and sclera. The origin of the nevus is still unclear. Several hypotheses suggest a reactivation of melanocytes during their migration from the neural crest. The pruritus reported in our patient may be explained by the increased quantity of mast cells observed in the lesion and/or neuronal stimulation of the ophthalmic and maxillary divisions of the fifth cranial nerve.