Acrokeratosis verruciformis of Hopf: dermoscopic and histopathological study- Acrokeratosis verruciformis of Hopf (AVH) is an autosomal dominant genodermatosis. It is caused by a mutation in the ATP2A2 gene, located on chromosome 12q24. Both AVH and Darier disease are believed to be allelic disorders. Familial cases of AVH usually have early onset either at birth or childhood, while sporadic cases usually present later in life. Recently dermoscopy of AVH has been described in Clinical and Experimental Dermatology journal.
Two siblings, a 7-year-old boy and a 5-year-old girl born to nonconsanguineous parents presented with a 4-year history of multiple, asymptomatic, skin-coloured papules. The lesions were present mainly over the dorsal aspects of the forearms in the boy and ventral aspect of the forearm and the antecubital fossa in the girl.
Both patients had Fitzpatrick skin type IV. Rest of the cutaneous, mucosa, hair and nail examination were within normal limits. An excisional biopsy from a papule on each child showed a focal area of compact hyperkeratosis, papillomatosis with church spire appearance, hypergranulosis and acanthosis confirming the diagnosis of AVH.
Dermoscopic examination using polarized contact dermoscopy of the two patients revealed structureless skin coloured to yellowish areas with whitish dots and streaks. Some papules, especially the larger and less keratotic lesions, showed uniformly distributed dotted vessels. Few papules showed a cerebriform pattern too. Under nonpolarized contact dermoscopy, the papules featured irregular white homogeneous areas, a white network and a cobblestone appearance.
A recently published case by Rajan et al also showed central white homogeneous areas, a central white network, peripheral cobblestone appearance, multiple brown pigmented dots arranged radially in the periphery (sunray appearance) over acral papules and regularly arranged brown dots with background erythema in the nonlesional skin on polarized dermoscopy.2
AVH is a chronic disease characterized by flat-topped keratotic papules, typically observed on the dorsa of the hands and feet. The classic histopathological features include hyperkeratosis, papillomatosis with 'church spire' appearance, acanthosis and hypergranulosis. Clefts in the granular layer with several acantholytic keratinocytes have also been reported in AVH. So histopathology finally confirms the diagnosis.
To conclude dermoscopy can be helpful to diagnosis AVH and may help to eliminate the need for biopsy for diagnosis but robust studies on the disease are required to finally arrive at a conclusion.
Source-
1. Genedy R, Taha A. Acrokeratosis verruciformis of Hopf: dermoscopic and histopathological study of two siblings. Clin Exp Dermatol. 2021 Oct;46(7):1313-1314. doi: 10.1111/ced.14691. Epub 2021 May 10. PMID: 33866599.
2. Rajan MB, Bains A, Vedant D. Dermoscopy of acrokeratosis verruciformis of hopf. Indian Dermatol Online J 2021; 12: 374–5.