<i>Paederus</i> dermatitis presenting with kissing lesions in a 12-year-old boy

A 12-year-old boy presented with painful erythematous lesions in the left infra-axillary region and on the medial aspect of the proximal upper arm, without any systemic symptoms.e lesions appeared after the boy noticed a burning sensation in the affected areas the night before, following an outdoor activity during the rainy season.Examination revealed well-demarcated erythematous plaques with vesicles, pustules, and a central zone of dusky erythema, displaying a mirror-image distribution in the infra-axillary area and the opposing medial proximal upper arm, indicative of "kissing lesions" [Figure 1].e boy had no history of similar episodes, insect bites, or contact with known allergens.Paederus dermatitis, also known as blister beetle or Nairobi fly dermatitis, is an irritant contact dermatitis caused by exposure to the coelomic fluid of the Paederus beetle, which contains the potent toxin pederin.is condition is particularly common in tropical and subtropical www.cosmoderma.org