Tinea corporis due to trichophyton rubrum in a woman and tinea capitis in her 15-day-old baby: molecular evidence of vertical transmission

We report a case of a 40-year-old Caucasian woman who came under our observation with a 7-year history of a chronic erythematous scaly dermatitis, diagnosed as psoriasis, involving gluteal area and thighs, and treated with topical steroids without benefit. During pregnancy, a progressive worsening of her condition and an extension of cutaneous lesions were observed. Her newborn, a 15-day-old girl, presented a similar scaly and squamous lesion on her scalp. Mycological examination was positive for Trichophyton rubrum in both cases, and random amplified polymorphic DNA analysis confirmed the isogenicity of the two isolates. We performed a diagnosis of T. rubrum tinea corporis and tinea capitis. The case we describe illustrates an unusual clinical presentation of tinea corporis with remarkable extension of cutaneous lesions due to the diagnostic delay and the continuous use of local steroids, together with a rare tinea capitis in the newborn. Our experience highlights the possibility of mother-child transmission and the importance of an early diagnosis.