Two women, aged 27 and 45 years, presented to the Dermatology Outpatient Clinic with acne vulgaris. Both had nodular acne in a similar distribution over the cheeks, chin, and perioral areas (Fig. 1). Each had a history of acne vulgaris as a teenager. Both were healthcare assistants working in the Singapore General Hospital throughout the severe acute respiratory syndrome (SARS) crisis, had worn N95 masks continuously for about 3 months whilst on the wards, and had suffered an outbreak of acne of the skin occluded by the mask. They were treated with topical retinoid and systemic antimicrobials, and both responded well.