Keratosis Follicularis Spinulosa Decalvans: A Report of Three Cases.

Keratosis follicularis spinulosa decalvans is a disorder affecting the hair follicles characterized by scarring alopecia of the scalp, eyebrows, and axillae, sometimes associated with photophobia and keratoderma. Being X-linked, it is more commonly seen in males but can be rarely seen in females also. We report three cases of this rare disorder including one in a female.

INTRODUCTION

Keratosis follicularis spinulosa decalvans (KFSD) is a hereditary disorder of the hair follicle which presents with scarring alopecia and follicular papules affecting the scalp and other areas of the body. It usually follows an X-linked pattern of inheritance, but sporadic and autosomal dominant cases can also be seen.

CASE REPORTS

Our first case was an 18-year-old female who complained of progressive hair loss over the scalp since 10 years and over the eyebrows since 5 years. She gave no history of similar complaints in her family. On examination of the scalp, she had multiple patches of cicatricial alopecia with sparse hair in the frontal, parietal, and temporal areas of the scalp. Sparse hair over the eyebrows, eyelashes, axillae, and pubic area were noted [Figure 1]. She also had generalized dry skin and multiple follicular papules over upper and lower limbs and buttocks [Figure 2].

Figure 1

Follicular papules and alopecia seen over the scalp along with sparse eyebrows and eyelashes

Figure 2

Follicular keratotic papules over dorsum of hand

Our second case was a 26-year-old male with decreased hair growth over scalp and body. He had no family history of similar complaints. On examination, he had diffuse alopecia of the scalp with sparse hair over eyebrows, eyelashes, and beard area. Multiple keratotic papules were noted over the scalp, upper limbs, and abdomen [Figures 3 and 4].

Figure 3

Sparse hair and papular lesions noted over the scalp

Figure 4

Follicular papules seen over abdomen

The third case was a 23-year-old male with complaints of decreased hair over scalp and body with skin lesions over the trunk. He gave a history of similar but milder complaints being present in his younger brother suggesting X-linked inheritance. On examination, he had alopecia over the crown area of the scalp [Figure 5], with sparse hair over the eyebrows and axillae, multiple follicular papules over the trunk and all four limbs. He also had associated palmoplantar keratoderma and nail dystrophy [Figure 6].

Figure 5

Scarring alopecia seen over scalp

Figure 6

Plantar keratoderma seen over the foot

Scalp biopsies from all three cases showed variable amounts of acanthosis and papillomatosis and dilated hair follicles filled with keratin plugs and entrapped hair shafts [Figures 7 and 8]. Dermis showed periadnexal mononuclear infiltrate. With clinicopathological correlation, they were diagnosed to have KFSD.

Figure 7

Dilated follicular infundibulum filled with keratin plug (H and E, ×40)

Figure 8

Entrapped hair shafts within hair follicle (H and E, ×40)

DISCUSSION

Keratosis pilaris atrophicans (KPA) is a group of cutaneous disorders which are characterized by follicular hyperkeratosis along with scarring. The following three disorders are considered to comprise the spectrum of KPA.[1]

KFSD

KPA faciei (KPAF) or ulerythema ophryogenes

Atrophoderma vermiculatum.

KFSD (OMIM 308800) is a rare X-linked disorder of the hair follicle. The term was first used by Siemens[2] in 1926 when he reported the disorder in a Bavarian family.

The locus of mutation has been localized to Xp22.13–22.2.[3] The candidate gene suggested is the membrane-bound transcription factor protease site 2 (MBTPS2) gene which is required for cleavage of sterol regulatory element-binding proteins (SREBPs). Altered SREBP cleavage impairs cholesterol and lipid homeostasis in the skin causing defective epidermal differentiation.[4]

Males are more commonly and severely affected than female heterozygotes in families having an X-linked inheritance pattern. However, some cases can be sporadic or be autosomal dominantly inherited.[5]

The age of onset is early in life with keratotic papules appearing initially on the face and later on the trunk and limbs.[5] As the disease progresses, cicatricial alopecia ensues on the scalp, eyebrows, and eyelashes along with the loss of hair in axillary and pubic areas.[6]

Some patients have associated photophobia and palmoplantar keratoderma. Other associations reported include woolly hair[7] and acne keloidalis nuchae with tufted folliculitis.[8]

The most important differential diagnoses include ichthyosis follicularis alopecia photophobia (IFAP) syndrome and Graham Little Piccardi Lasseur syndrome (GLPLS).

IFAP syndrome is an allelic disorder, being genotypically and phenotypically similar to KFSD. Thus, both represent a different phenotypic manifestation of the same mutation. Both are caused by the mutation in the MBTPS2 gene.[9] Clinically, both disorders present with alopecia and follicular hyperkeratosis. However, the alopecia in IFAP syndrome is of the nonscarring type while that in KFSD is scarring. Furthermore, ocular features like photophobia and corneal dystrophy are essential for the diagnosis of IFAP.[1]

GLPLS is a variant of lichen planopilaris which presents with scarring alopecia of the scalp, nonscarring alopecia of axillae and pubic region, and keratotic follicular spinous papules over a body. The distinction from KFSD is made mainly on histopathology which reveals changes suggestive of lichen planus including vacuolar degeneration and interface dermatitis.[10]

Treatment of KFSD is usually unsatisfactory. Topical treatment comprises mainly of keratolytics and emollients. Systemic retinoids like isotretinoin and etretinate are beneficial in the early stages of the disease as they downregulate follicular hyperkeratosis and inflammation.[6] Dapsone was found to be useful due to its inhibition of leukocyte chemotaxis and stabilization of lysosomal enzymes.[11] Other treatments tried include antibiotics, intralesional and topical steroids. Hair reduction lasers have also been tried.[12]

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Conflicts of interest

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