Nonfamilial acrokeratosis verruciformis of Hopf.

Acrokeratosis verruciformis (AKV) of Hopf is an autosomal dominant genodermatosis with unknown etiology. It is characterized by multiple flat-topped keratotic papules resembling planar warts located mainly on the dorsum of hands and feet. Superficial ablation is the treatment of choice. A 41-year-old female presented with multiple hyperpigmented, hyperkeratotic papules and plaques over flexor aspect of both forearms, extensors of both legs and dorsum of the feet. Histopathology showed changes of AKV. Patient was treated with a combination of topical corticosteroids and cryotherapy with no visible improvement.

INTRODUCTION

Acrokeratosis verruciformis (AKV) of Hopf is a very rare heritable hyperkeratotic dermatosis that was originally described by Hopf in 1931.[1] It is an autosomal dominant genodermatosis with unknown etiology affecting both sexes, more common in males when compared to females with a ratio of 5:1.3. The lesions are usually present at birth, but they may appear later in infancy as papules or at puberty as ichthyosis. In some cases, onset may be delayed until the fifth decade of life.[2]

Acrokeratosis verruciformis of Hopf is characterized by multiple flat-topped skin colored, dull red to brown colored keratotic papules resembling planar warts mainly on the dorsum of hands and feet.[3] Superficial ablation is the treatment of choice while other modalities include retinoic acid, cryotherapy and CO2 laser. Herein, we report a case of AKV presented with extensive lesions over legs as well as involvement of the flexors.

CASE REPORT

A 41-year-old female presented with multiple raised lesions over the body since two years. Lesions initially developed over both forearms and gradually involved the lower limbs and back. There was no history of similar complaints among the family members or any seasonal variation. She gave a history of pulmonary tuberculosis several years ago, for which she took antitubercular therapy. Examination revealed multiple hyperpigmented, hyperkeratotic papules and plaques over flexor aspect of both forearms [Figure 1], extensors of both legs and dorsum of the feet [Figure 2]. A few discrete hyperkeratotic and hyperpigmented papules were present over the back. There were no nail changes or oral lesions. Biopsy was taken from a lesion over the shin of the left leg keeping AKV of Hopf, lichen amyloidosis and localized Darier's disease as differentials.

Figure 1

Multiple hyperpigmented, hyperkeratotic papules and plaques over the flexor aspect of right forearm

Figure 2

Multiple hyperpigmented, hyperkeratotic papules and plaques over extensor of both legs and dorsum of feet

Histopathology showed hyperkeratosis, hypergranulosis, acanthosis, and papillomatosis, the latter associated with circumscribed elevation of the epidermis (church spires) and elongation of rete ridges. The dermis showed a mild inflammatory infiltrate [Figure 3]. Based on clinical and histological findings, case was diagnosed as nonfamilial AKV. Patient was treated with potent topical corticosteroids along with multiple sittings of cryotherapy (liquid nitrogen) for 3–4 months. She was lost in follow up due to lack of appreciable improvement.

Figure 3

Papillomatosis with circumscribed elevation of the epidermis (church spires) and elongation of the rete ridges (H and E, ×40)

DISCUSSION

Acrokeratosis verruciformis is a rare heritable, hyperkeratotic dermatosis of unknown etiology, characterized by multiple, localized, symmetrical, flat, skin colored, wart-like lesions, located mainly on the dorsum of hands and feet.[3] Isolated papules may develop on knees, elbows, forearms, as well as other parts of the body.[24] Forehead, scalp, flexures, and oral mucosa are never affected, as reported by Panja.[4] Lesions may be finely granular to lichenified papules.[5] Interruption of dermal ridges with puntate pits may be seen in the finger pads and palms.[456] Nails show whitish discoloration, thickening and may have longitudinal ridges, with breakage at the distal ends.[56] Histopathology classically shows the hyperkeratosis without parakeratosis, hypergranulosis and acanthosis. Papillomatosis resembling a church spire helps in distinguishing the condition from other dermatoses.

Involvement of flexors along with extensive lesions over the extensors of legs was unusual in our case in contrast to the classical AKV. Involvement of both legs and forearms with warty papules has been reported, without involvement of the dorsum of the hands and feet.[7] Appearance of disease in late adolescence and an absent family history was also unusual. Nonfamilial cases have been reported.[89] The age of onset of classical AKV is during childhood while it is much later in sporadic AKV.[8] Similarly, palmar and plantar keratosis has been reported in classical, but not sporadic AKV.[8] In our patient, the onset was in late adolescence with no involvement of palms and nails, a feature of sporadic AKV. Dhitavat et al., have reported novel P602 L mutation within the ATP binding domain of ATP2A2 in classical AKV[10] while, Berk et al., reported an A698V codon change in ATP2A2 in sporadic AKV.[11]

Skin conditions that should be included in the clinical differential diagnosis of AKV are epidermodysplasia verruciformis, planar warts, and seborrheic keratosis. Diagnosis needs to be confirmed by histopathology. In our case, morphology was more in favor of Lichen amyloidosis and Darier's disease. The unique finding of AKV is ‘church spire’ papillomatosis[12] that was diagnostic in our case, in contrast with benign dyskeratosis and corps ronds of Darier's disease[12] and amyloid accumulates in the dermal papillae of lichen amyloidosis.

The only treatment considered effective for AKV is superficial ablation. Applications of retinoic acid, cryotherapy or destructive lasers such as CO2 or Nd:YAG have also been tried. Lesions tend to persist throughout life and become more prominent after prolonged sun exposure.[2]

CONCLUSION

The case is reported due to its rarity in the form of extensive lesions and the flexural involvement, absent family history along with delayed onset of the lesions in a female.