O'Brien's actinic granuloma in association with prolonged doxycycline phototoxicity.

O'Brien's actinic granuloma is clinically characterized by annular papules and plaques on sun-exposed areas of skin. These lesions often occur insidiously on a background of severe solar elastosis; however, an acute variant following sunburn has been reported in the literature. We present two cases of acute actinic granuloma precipitated by episodes of sunburn occurring on a background of prolonged doxycycline phototoxicity. Biopsies from both patients showed a histiocytic infiltrate with multinucleate giant cells engulfing elastotic material, with a reduction of elastin towards the centre of the papule. Marked resolution of the lesions was noted after 8 weeks of treatment with betamethasone dipropionate 0.05% ointment in optimized vehicle together with adequate photoprotection in the form of broad-spectrum sunscreens.