[Measles: a follicular disease]

Since the year 2000, measles epidemics have occurred throughout Europe, with a number of severe cases in adults leading to hospitalisation. Herein, we discuss the case of a young adult male with measles presenting clinical and histological features of rash having a follicular nature.

An 18-year-old male consulted for diffuse, febrile morbilliform exanthem consisting chiefly of follicular papules surrounded by erythematosus macules. In the absence of any features suggesting possible contagion or implicated medication, biopsy was performed on one of these elements and showed strictly follicular involvement. Perifollicular lymphocytic inflammation was noted, with necrotic keratinocytes having monster nuclear cells, and above all, multinucleated cells within the outer root sheath and the sebaceous gland. Positive IgM measles serology was noted.

Follicular involvement is a very common feature in cases of measles that we have seen in recent years. In the present case, histological examination showed a follicular and sebaceous cytopathogenic effect, which while far less well known, has occasionally been seen with measles in the sweat glands or the epidermis, in which viral presence was detected. Thus, the skin rash was accounted for at least in part by the presence of the virus itself within keratinocytes and adnexal cells. This follicular involvement of measles, histologically confirmed in the present case, is frequently seen and can be helpful in differential clinical diagnosis with regard to other viral rashes. It could be caused by special affinity of the virus for body hairs.