Peculiar Pattern of Irritant Contact Dermatitis to Semecarpus anacardium

Semecarpus anacardium (Family: Anacardiaceae), is a frequently used medicinal plant in alternative medicine. There has been few case reports suggesting the role of marking nut extract in allergic contact dermatitis. Case one presented with vesicles coalescing to form bullae with surrounding necrotic epidermis accompanied by itching and burning sensation over nape of neck. He developed recurrent urticarial episodes post treatment. Case two reported similar lesions over beard region after 2 weeks of our index case in addition to diffuse erythematous maculopapular pruritic rash over upper chest, face and anterior shoulder. Case three, four and five reported with similar kind of lesions over various body parts. Case six presented with targetoid lesion with central bullae over upper torso. Case seven reported with bizarre lesions like splattering of chemical which were morphologically similar as the other cases, over left popliteal fossa and calf area. Our cases were from the same geographic area and were in the same profession. On evaluation of the pattern and morphology of lesions and careful investigation, it was concluded that it was an irritant reaction to Semicarpus nut extract which was supported by histopathology findings. On further probing, it was observed that the individuals inflicted the injury in order to avoid some strenuous work. All were evaluated and none of them were found to be suffering from any psychiatric ailment. We reported this case series because of unique morphological presentation which has not yet been reported in the literature to the best of our knowledge.