Eruptive Vellus Hair Cysts Differential Diagnoses

Updated: Jul 29, 2019
  • Author: Stephanie Juliet Campbell, DO; Chief Editor: Dirk M Elston, MD  more...
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DDx

Diagnostic Considerations

A single report describes eruptive vellus hair cysts (EVHCs) on the face, leading to blue-gray discoloration of the skin and mimicking nevus of Ota. [15] A single case reported EVHCs in association with syringomas. [16]

EVHCs have been reported in 2 cases of pachyonychia congenita. [17, 18] Pachyonychia congenita is an autosomal dominant disorder associated with palmoplantar hyperkeratosis, dystrophic nails, oral leukoplakia, follicular hyperkeratosis, and corneal abnormalities. Several cases have been associated with other types of multiple cutaneous cysts (eg, steatocystoma multiplex, epidermoid cysts).

A case report has also linked EVHCs with hidrotic ectodermal dysplasia. [19] The patient had sparse hair and disabling palmoplantar hyperkeratosis. Incidentally, the patient was taking oral etretinate at 1 mg/kg/d for more than 2 years, which resulted in improvement of her keratoderma but did not alleviate the EVHCs.

EVHCs have also been reported in association with anhidrotic ectodermal dysplasia. [20] In anhidrotic ectodermal dysplasia, patients have a greatly reduced number of eccrine sweat glands and sebaceous glands, resulting in difficulties with temperature regulation. Other clinical features include sparse hair, brittle nails, and teeth abnormalities.

Two cases of eruptive vellus hair cysts were reported in association with renal failure. Both cases were reported in 58-year-old Japanese patients with acquired renal disease on hemodialysis. [21] EVHCs were confirmed by skin biopsy from the cervical region in both cases. They hypothesize that advanced glycation end product may play a role in the development of the cystic structures in these patients; however, cause and effect have not been shown.

A possible link has been suggested between neurologic abnormalities and EVHCs. Morgan et al [22] reported a patient with developmental delay, mild intellectual impairment, and congenital EVHCs. They noted 2 other patients with incidental seizure disorders and EVHCs as corroborating evidence; however, at this point, no definite evidence supports a new neurocutaneous syndrome involving EVHCs.

One report describes EVHC occurring in a patient with Lowe syndrome. Lowe syndrome is an X-linked recessive oculocerebrorenal syndrome with mutations of Xq24-26.1. The authors suggest that a defect in the oculocerebrorenal-Lowe 1 gene (OCRL1) may account for the cyst formation. Features of Lowe syndrome include renal failure, mental retardation, and eye abnormalities. [23]

Differential Diagnoses