Some clinical cases of generalized verrucous epidermal nevus are difficult to diagnose. Hence, we demonstrate the effectiveness of using a diagnostic algorithm to identify generalized verrucous epidermal nevus for a case report from our own clinical practice. The patient had congenital skin rash that was not characterized by spreading or spontaneous involution. It bilaterally affected skin of the head, neck, body and flexor surface of extremities along the lines of Blaschko as light or dark-brown wart-like structures shaped like stripes and curls resembling 'mud splashes'. Laboratory testing revealed no significant deviation from the norm. Consultations with experts in adjacent disciplines showed no concomitant pathologies. Histological examination of a bioptate collected from the pathological focus revealed hyperkeratosis, papillomatosis, moderate acanthosis, the non-uniform granular layer, and scarce perivascular lymphohistocytic infiltrates (i.e., changes typical of verrucous epidermal nevus). Differential morphological diagnosis showed that the patient did not have the Bloch-Sulzberger syndrome or other diseases manifesting as papillomatous eruptions. Thus, the proposed diagnostic algorithm included allowance for anamnestic and clinical examination data, laboratory testing, meticulous morphological analysis of the histologic patterns during examination of biopsy specimens, and differential diagnosis along with consultations with experts in the adjacent fields. The algorithm proved to be efficient for identifying the dermatologic pathology.