[Granuloma annulare following BCG vaccination]

Granuloma annulare following BCG vaccination or tuberculin skin tests is rarely reported in the literature. We describe three cases occurring in patients under the age of 6 years.

In the first two cases, granuloma annulare was initially localized at the vaccinal site, then generalized. In the third case, diagnosis was deep granuloma annulare localized far from the initial vaccination site, with recurrence following tuberculin test. In the three cases, diagnosis was made on the basis of clinical and histological elements.

The relationship between granuloma annulare and BCG may seem evident when the eruption occurs at the vaccinal site, but remains difficult to prove. Diagnosis essentially relies on the absence of other classical etiologies and a compatible delay. When a vaccination such as BCG appears to be the cause of granuloma annulare, a possible cause would be injection trauma or a cell-mediated-delayed-hypersensitivity reaction to a specific antigen contained in the vaccine, leading to development of skin disorders such as granuloma annulare in predisposed subjects. Reports of granuloma annulare following BCG are uncommon but the incidence may be underestimated. In practice, diagnosis of granuloma annulare following BCG or tuberculin skin test cannot be established until BCG dissemination infection is ruled out, a necessary clinical and paraclinical step required in all cases of eruptions following this vaccination. Granuloma annulare is a benign complication requiring no treatment and does not constitute a contraindication for other usual vaccinations.