Tinea incognito due to Microsporum canis in a 76-year-old woman

Abstract

A 76-year-old housewife presented with multiple erythematous itchy patches on her face and neck along with hair loss, scaling and inflammation in the occipital region of the scalp that had started 2 months ago. The diagnosis of allergic contact dermatitis was made in the first place and therapy with topical corticosteroid creams was recommended.Physical examination revealed multiple erythematous scaly papules and plaques on her face, neck and upper trunk ( Fig. 1). Scalp examination revealed intense inflammation and scaling along with hair loss in the occipital region ( Fig. 2). Direct microscopy of scraping specimens from skin lesions and scalp was positive for fungal hyphae. Woodlight inspection of scalp revealed green fluorescence. Fungal culture on Sabouraud's agar grew Microsporum canis. The patient was successfully treated with oral itraconazole as a pulse therapy for 3 months and 1% clotrimazole cream twice daily.Topical application of steroids may modify the clinical picture showing several atypical forms of tinea including lupus erythematosus, rosacea, contact dermatitis and even erythema migrans [1]. Potent fluorinated steroids seem most likely to produce tinea incognito, however, even steroids of the lowest potency as 1% hydrocortisone cream can modify clinical presentation of tinea [2]. More recently, a few cases of tinea incognito due to use of topical tacrolimus and pimecrolimus were reported in literature [3].The present case highlights the importance of considering a dermatophytosis when clinical presentation of dermatosis is atypical, or in an atypical location for fungal infection given the age of the patient. References 1. Gorani A, Schiera A, Oriani A (2002) Case report. Rosacea-like tinea incognito. Mycoses 45: 135-137 2. Al Aboud KA, Al Hawsawi KA, Alfadley A (2003) Tinea incognito on the hand causing a facial dermatophytid reaction. Acta Derm Venereol 83: 59 3. Crawford KM, Bostrom P, Russ B, Boyd J (2004) Pimecrolimus-induced tinea incognito. Skinmed 3: 352-353

Bullous Tinea Incognito in a Bulgarian Child: First Description in the Medical Literature!

“…Tinea incognito is practically a classical mycosis treated with a topical corticosteroid, which leads to demasking of clinical symptoms and often to the imitation of another type of skin disease [ 1 ]. Microsporum Canis is a dermatophyte fungus in which cats and dogs are recognised as the natural hosts [ 2 ].…”

“…M. canis is also easily transmitted to humans, causing lesions to the glabrous skin (tinea corporis) and the head (tinea capitis) [ 2 ]. Depending on the severity of clinical symptoms, systemic treatment could last between 2 weeks and approximately a month.…”