Clinical photography of a linear epidermal nevus. This image captures a single, elongated, hyperpigmented plaque with a slightly verrucous surface and mild keratotic scaling, arranged in a linear/serpiginous pattern along the skin. The lesion appears well circumscribed, non-inflammatory, and located on the cutaneous surface without obvious regional lymphadenopathy or ulceration. The distribution follows Blaschko's lines, a hallmark feature of epidermal nevi, indicating a mosaic somatic mutation in keratinocytes. The color ranges from light brown to tan with focal darker hyperpigmented conglomerates; surface texture is rough with papillomatous outgrowths at the margins. The image is a high-resolution clinical photograph (macroscopic close-up) without dermoscopic magnification or contrast enhancement. In suspected cases, histopathology would typically show hyperkeratosis, acanthosis, and slight papillomatosis with elongation of rete ridges, consistent with an epidermal nevus. Clinically, linear epidermal nevi are usually benign but can be associated with epidermal nevus syndrome if extensive or multisystemic. Differential considerations include inflammatory linear verrucous epidermal nevus (ILVEN), linear porokeratosis, and epidermal keratinocytic nevi of other distributions. The image is valuable for dermatology education, pattern recognition, genetic counseling discussion, and patient counseling about cosmetic management or laser/ablative therapy options. Proper documentation supports diagnosis, prognosis assessment, and multidisciplinary treatment planning for patient care.

This composite educational image illustrates the clinical and histopathological features of Inflammatory Linear Verrucous Epidermal Nevus (ILVEN). Panel A presents clinical photographs showing erythematous to violaceous, scaly papules and plaques. These lesions exhibit a distinct linear arrangement following the Lines of Blaschko, extending from the right pectoral region down the upper extremity to the dorsal aspect of the fingers. Panels B and C are high-power photomicrographs (H&E stain) of skin biopsies from the chest and wrist. Pathological findings include marked epidermal acanthosis and spongiosis. A key diagnostic feature shown is the characteristic horizontally alternating pattern of orthokeratosis and parakeratosis within the stratum corneum. The underlying papillary dermis reveals a superficial perivascular lymphocytic infiltrate. This presentation is a classic example used in dermatology to differentiate ILVEN from other Blaschkoid dermatoses such as linear psoriasis or lichen striatus based on chronicity and specific histomorphological patterns.

This is a high-resolution clinical photograph of a cutaneous epidermal nevus located along the left shoulder and anterior upper chest. Modality: clinical photography; technique: standard color image, with even lighting to depict surface texture and pigmentation; no dermoscopy or adjunct contrast used. The lesion demonstrates a classic Blaschko-linear distribution, a left-to-right, anterior-lateral cascade that follows embryologic skin cleavage lines. The primary subject is an epidermal nevus arising from keratinocyte proliferation within the epidermis, presenting as hyperpigmented, verrucous plaques that are well demarcated and mildly raised. In skin of colour, the pigment intensity may be accentuated, producing dark brown to black plaques with subtle scale and ridging; surface may be minimally hyperkeratotic. The pattern is typically unilateral and unilateral to the trunk and proximal limbs, with linear arrays aligning with Blaschko lines. Clinically, these lesions are generally benign but can be cosmetically disfiguring; differential considerations include inflammatory linear verrucous epidermal nevus (ILVEN), linear porokeratosis, and other pigmentary mosaicisms. Pathology, if pursued, would show acanthosis, hyperkeratosis, and mild papillomatosis without significant atypia. This image is useful for dermatology education, mosaicism concepts, and digital documentation in genodermatoses clinics. Helpful for patient counseling, telemedicine assessment, and research on Blaschko-linear cutaneous disorders in diverse populations.

Clinical photography of an inflamed, linear, verrucous skin plaque consistent with inflammatory linear verrucous epidermal nevus (ILVEN) located on the forearm. The lesion appears as a long, narrow band of scaly, hyperkeratotic plaques with erythematous border and mild crusting. The linear distribution follows Blaschko lines, a characteristic pattern for epidermal nevi. Visual features include raised, rough surface texture, intermittent excoriations, and focal remodeling of surrounding epidermis. Inflammation manifests as surrounding erythema and subtle edema with secondary flaking. The lesion length spans several centimeters with variable width, tapering at the ends. There is no evidence of systemic involvement. The image is a standard clinical dermatology photograph without dermoscopic magnification or histologic confirmation. ILVEN typically presents in infancy or early childhood but can be seen later; it is often intensely pruritic and recalcitrant to routine emollients, requiring targeted therapy. Histopathology, if obtained, would show alternating areas of hypergranulosis and hypogranulosis with psoriasiform epidermal hyperplasia and inflammatory infiltrate, supporting an ILVEN diagnosis. This image supports clinical recognition, differential diagnosis against linear psoriasis, verrucous epidermal nevus, and lichen striatus, and can aid educational discussions, patient counseling, and treatment planning including topical steroids, retinoids, or laser therapy.