Keratosis Follicularis (Darier Disease) Workup

Updated: Oct 01, 2020
  • Author: Pui-Yan Kwok, MD, PhD; Chief Editor: Dirk M Elston, MD  more...
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Other Tests

With the discovery that mutations in ATP2A2 cause keratosis follicularis (Darier disease), gene sequencing can be used to confirm the diagnosis.



A skin biopsy is helpful in confirming the diagnosis of keratosis follicularis (Darier disease).


Histologic Findings

Acantholysis (loss of epidermal adhesions) and dyskeratosis (abnormal premature keratinization) are the 2 main features of keratosis follicularis (Darier disease). Acantholysis frequently results in the formation of characteristic suprabasal clefts (lacuna) (see the image below). The underlying dermal papillae, covered by a single layer of epithelium (stratum basale), project into these clefts and form villuslike structures. A large keratin plug, often showing focal parakeratosis, overlies each lesion. Hyperkeratosis is also common.

Acantholysis and dyskeratosis (abnormal keratiniza Acantholysis and dyskeratosis (abnormal keratinization) are the 2 main features of Darier disease. Loss of epidermal adhesion with acantholysis frequently results in the formation of suprabasal clefts (lacunae).

Two types of dyskeratotic cells are present: corps ronds and grains. Corps ronds are predominantly located in the stratum spinosum and the stratum granulosum. Corps ronds are characterized by an irregular eccentric and sometimes pyknotic nucleus, a clear perinuclear halo, and a brightly eosinophilic cytoplasm. Grains are mostly located in the stratum corneum, and they consist of oval cells with elongated cigar-shaped nuclei and abundant keratohyalin granules. Diagnostic histologic changes are often focal, necessitating a careful search.