Case: A 12-year-old schoolboy presented to the outpatient clinic with a three-day history of pruritic, erythematous raised lesions on his hands. Clinical examination revealed multiple erythematous papules with punctate hemorrhagic excoriations arranged in a linear pattern, originating from the first web space and extending toward the forearm bilaterally. Dermoscopic evaluation demonstrated localized brown-black dots with golden brownish background suggestive of hemorrhagic bite sites in a linear configuration.. Based on these findings, a diagnosis of bed bug bite (Cimicosis) was established, characterized by the classic “breakfast, lunch, and dinner sign,” indicative of sequential clustered bite marks corresponding to the bug’s movement. Differential diagnoses, including scabies and paederus dermatitis, were excluded due to the absence of burrows or involvement of other typical predilection sites, vesicular lesions, and burning sensation.

Teaching point: This case highlights the importance of dermoscopy in distinguishing common insect bite dermatoses like scabies, cimicosis, paederus dermatitis presenting with similar findings. Haemorrhagic spots due to bite marks of bed bug along with brownish area due to hemosiderin deposition in a characteristic linear Breakfast, lunch and dinner sign manner provides a useful diagnostic clue to Cimicosis.