BCG-induced lichen scrofulosorum.

We report the case of a 2 month old boy who developed lichen scrofulosorum one month after Bacillus Calmette-Guerin inoculation. Existence of extracutaneous tuberculosis was excluded. A possible dysfunction of the interleukin-12 / interferon-gamma axis was suggested by cellular assays, although further genetic testing was negative. Vaccine-related adverse events are infrequent but they may reveal an underlying immune disorder, highlighting a need for proper investigation, referral and follow-up.