Keratosis Follicularis Spinulosa Decalvans, Autosomal Dominant

Description

Keratosis follicularis spinulosa decalvans (KFSD) is an uncommon genodermatosis characterized by follicular hyperkeratosis, progressive cicatricial alopecia, and photophobia. Most reported cases show X-linked inheritance (KFSDX; 308800) (Castori et al., 2009).

Clinical Features

Bellet et al. (2008) reported a father, son, and daughter with keratosis follicularis spinulosa decalvans. The son presented at age 17 years with hair loss. He reported dryness and flaking of his scalp at the age of 10 years, which progressed to lesions and permanent hair loss. Keratosis pilaris was present on the extensor surfaces of the upper and lower extremities bilaterally. Other features included facial erythema, thin eyebrows, and mild photophobia. He had mild asthma. His 50-year-old father described a similar pattern of hair loss over the mid scalp and vertex beginning at age 27 years, in addition to photophobia that had been noted since early childhood. The patient's 12-year-old sister also had scalp lesions, facial redness, thin eyebrows, and photophobia, but no hair loss. Skin biopsy of the son's lesions showed concentric perifollicular fibrosis with a moderately dense inflammatory cell infiltrate. The disorder was refractory to multiple treatments. Bellet et al. (2008) postulated autosomal dominant inheritance.

Castori et al. (2009) reported a 3-generation Italian family in which 5 individuals had keratosis follicularis spinulosa decalvans. The pedigree pattern was consistent with autosomal dominant inheritance, and male-to-male transmission was observed. The 5-year-old male proband had multiple follicular pustules localized to the occipital scalp and nuchal area since age 3 years. He also had had diffuse cheek erythema since the first months of life. Other features included dystrophic nails, photophobia, recurrent blepharitis, keratitis, and multiple dental caries due to enamel hypoplasia. There was scarring alopecia and folliculitis over the occiput, sparse eyelashes and eyebrows, and follicular keratotic papules on the trunk and extensor surfaces of the limbs. Sweating, body hair, and hearing were normal. Scalp skin biopsy showed epidermal hyperplasia and a dense perifollicular inflammatory infiltrate composed of lymphocytes and neutrophils. The father had recurrent folliculitis of the scalp, trunk, and buttocks, with progressive hair loss since puberty. He also had multiple caries with consequent extensive tooth extraction, photophobia, and recurrent blepharitis since early childhood. Eyelashes and eyebrows were sparse, and toenails were thick and dystrophic. The proband's 2 sibs were similarly affected, and the proband's paternal grandfather was reportedly affected. In a literature review of 47 cases, Castori et al. (2009) noted that there had been several reports of families with KFSD showing suspected autosomal dominant inheritance rather than classic X-linked inheritance. Additional features, such as nail dystrophy and enamel hypoplasia, appeared to be less common in the X-linked form.