Actinic folliculitis is a rare pustular dermatosis triggered by sun exposure. The eruption appears within 4-24 hours of sun exposure, typically on the face but sometimes on the arms, back, and upper chest as well. It usually resolves in 7-10 days, but it can take up to 3 weeks to resolve. Cases typically occur in the spring, and recurrence with repeat sun exposure is common, although the phenomenon of hardening has been reported.

This condition is usually reported in patients aged 17-42 years. It encompasses the previously reported diagnoses of acne aestivalis and actinic superficial folliculitis. Pathogenetically, it is thought that ultraviolet A (UVA) induces epidermal, including infundibular, thickening and follicular occlusion.