Dermatitis linearis caused by Paederus colombinus in Colombia: A review and case series

Abstract

Background: Dermatitis linearis caused by Paederus spp is a distinct type of contact dermatitis, characterized by the presence of erythematous and vesicular lesions on exposed areas of the body, which usually follow a linear pattern of distribution. It is caused by toxins contained in the endolymph of Paederus beetles, which belong to the class Insecta, order Coleoptera (beetles), family Staphylinidae (rove beetles), subfamily Paederinae, tribe Paederini, subtribe Paederina. Methods & Materials: We present a series of five selected cases that reflect the clinical and epidemiological spectrum of this clinical entity from a recent outbreak in two departments of Colombia. The aim of the study is also to report the occurrence of the first outbreak ever reported in Colombia. A thorough physical examination was performed obtaining a detailed description of the cutaneous lesions and looking for signs and symptoms of systemic affection. Paederus beetles recovered from patient's dwellings were submitted for entomological identification. Results: Affected patient ages ranged from 32 to 50 years old, with an average of 42 years old and a female predominance. Lesions presented as eczema with latent burn sensation (60%); as erythematous maculopapular lesions (20%) and papular and erythematous lesions (20%). In all cases, lesions were accompanied by burning / stinging sensation (100%) with pruritus (20%). Afterwards the lesions became vesicular and finally squamous (100%) around the fifteenth day of evolution. In Latin America, reports of dermatitis linearis outbreaks are scarce. The present study reports the occurrence of the first confirmed cases in the Atlantic Coast of Colombia, along with a detailed clinical, entomological and epidemiological description of dermatitis caused by Paederus colombinus. Conclusion: This Paederus spp. dermatitis report represent the first ever described in Colombia, emphasizing on the correct approach for a successful diagnostic based on its differentiation from other common skin conditions such as herpes zoster and simplex, bullous impetigo, pustular psoriasis, phytophotodermatitis, Snedder-Wilkinson disease, mycotic infections and other allergic reactions.