Unilateral palmoplantar verrucous nevus

Unilateral Palmoplantar Verrucous Nevus (UPVN) is a rare skin condition characterized by the development of verrucous (wart-like) nevi (moles) predominantly on one side of the body, affecting the palms of the hands and/or the soles of the feet. This condition is a type of epidermal nevus, which is a broader category of skin lesions that are present at birth or develop early in life and consist of an overgrowth of cells found in the epidermis (the outer layer of the skin).

Etiology and Pathogenesis

The exact cause of Unilateral Palmoplantar Verrucous Nevus is not well understood. It is believed to result from postzygotic somatic mutations that occur during embryonic development, leading to mosaicism. These mutations affect the proliferation and differentiation of keratinocytes, the predominant cell type in the epidermis. Unlike hereditary conditions, UPVN does not follow a genetic inheritance pattern and occurs sporadically.

Clinical Features

Patients with UPVN present with well-demarcated, thickened, verrucous plaques that are limited to the palms and soles. The lesions are typically unilateral, affecting either the left or the right side of the body. The condition is usually present at birth or manifests in early childhood. Although the lesions are benign, they can cause discomfort or pain, especially when located on weight-bearing areas of the feet, leading to difficulties in walking or performing manual tasks.

Diagnosis

Diagnosis of Unilateral Palmoplantar Verrucous Nevus is primarily clinical, based on the characteristic appearance and distribution of the lesions. Dermoscopy, a non-invasive imaging technique, can aid in the diagnosis by revealing specific patterns associated with verrucous nevi. In uncertain cases, a biopsy may be performed to exclude other conditions and to confirm the diagnosis histologically. Histopathological examination typically shows hyperkeratosis, acanthosis, and papillomatosis, which are indicative of verrucous nevi.

Treatment

Treatment of UPVN is challenging and focuses on relieving symptoms and improving the cosmetic appearance of the lesions. Options include topical treatments, such as keratolytics (agents that soften and break down the keratin in the skin), and surgical interventions like laser therapy, cryotherapy, or excision. However, these treatments may not be completely effective and carry the risk of scarring or recurrence of the lesions.

Prognosis

The prognosis for individuals with Unilateral Palmoplantar Verrucous Nevus is generally good, as the condition is benign and does not affect overall health. However, the cosmetic and functional implications of the lesions can significantly impact the quality of life. Regular follow-up with a dermatologist is recommended to monitor the lesions and manage any complications.