Keratosis follicularis spinulosa decalvans: a rare cause of scarring alopecia in two young Indian girls.

Keratosis follicularis spinulosa decalvans (KFSD) is an X-linked xenodermatosis characterized by scarring alopecia and follicular hyperkeratosis. This condition mainly affects males with females being carriers and will have milder symptoms. We present two sisters with severe form of KFSD, progressing to scarring alopecia.

INTRODUCTION

Keratosis follicularis spinulosa decalvans (KFSD) is a type of scarring alopecia which is grouped under a broader term keratosis pilaris atrophicans (KPAs). The other two clinical entities under KPAs include KPA faciei and atrophoderma. Common to these conditions are keratotic follicular papules, non-purulent inflammation of variable degree, irreversible hair loss, and/or atrophic depression similar to pitted scars. Very few cases of KFSD have been reported in Indian literature.[123] We here present a case report of severe form of KFSD, a rare cause of scarring alopecia in 2 young Indian girls.

CASE REPORT

A 8-year-old female came to the clinic with complaints of hair loss over the scalp since 6 years with sparse eye brows. Hair loss was progressive in spite of trying Ayurvedic medicine and homeopathy. On examination hair density was reduced over the scalp with vellus and terminal hairs. Multiple follicular papules were seen giving roughness to the scalp [Figures 1 and 2]. Similar lesions were seen all over the back, chest wall, extensor aspects of limbs. There was no history of photophobia and ophthalmic examination showed no evidence of conjunctival/corneal involvement. Punch biopsies were taken and submitted for histopathological examination. Her 5 year old sister had similar complaints. Both the siblings were normal at birth, the above symptoms started from the age of 2 years. However, biopsy was not taken from the younger sibling. Histopathologic examination revealed hyperkeratosis and mild acanthosis of epidermis with follicular plugging and dilated infundibulum [Figure 3]. The dermis revealed perifollicular lymphocytic infiltrate with eccentric epithelial atrophy, polytrichia, and perifollicular fibrosis [Figure 4]. Periodicacid Schiffs (PAS) stain done did not show any fungal organisms. Considering family history and clinical features, a diagnosis of KFSD was offered.

Figure 1

Scalp showing sparse hairs and keratotic papules and sparse eyebrow hairs

Figure 2

Closer view of scalp showing sparse hairs and prominent keratotic papules (revised)

Figure 3

Microscopy – Epidermis shows follicular plugging, acanthosis, and mild hyperkeratosis (H and E, ×4)

Figure 4

Higher power showing perifollicular fibrosis and lymphocytic infiltrate (H and E, ×10)

DISCUSSION

The evaluation of hair loss is a diagnostic challenge to both dermatologist and pathologist. A good clinico-pathological correlation is very much essential. Alopecia can broadly be classified as scarring and non-scarring. KFSD is a rare type of primary scarring alopecia with lymphocyte predominance.[4]

KFSD is a rare genetic disorder with X-linked and autosomal dominant pattern of inheritance.[5] This condition was first described by Macleod,[6] but the term KFSD was used by Siemen in the year 1926.[7] The gene has been mapped to Xp21.2-p22.2.[8] Sporadic cases have also been described.[9] Clinically the condition is characterized by follicular hyperkeratosis and scarring alopecia. Follicular hyperkeratosis begins during infancy or early childhood, first on the face, affected the eyebrows, cheeks, forehead, and nose. Scarring alopecia of scalp, eyebrows begins in early childhood and progresses further. Other associated features include palmoplantar keratoderma, corneal dystrophy with photophobia, high periungal cuticles.[9] Occasional cases have been associated with Downs syndrome.[10]

In X-linked dominant inheritance pattern, men present with full blown disease, whereas female act as carriers and have milder form of disease.[11] Females with severe form of disease have also been reported.[311] These cases either had autosomal dominant pattern of inheritance and few cases were sporadic in onset. A theory of non-random X inactivation (process of lyonization) was proposed in cases with sporadic onset.[3] In present case report, both the sisters were affected without any other family members being involved. They may either have autosomal dominant pattern of inheritance or process of lyonization.

The differential diagnosis of KFSD include icthyosis follicularis alopecia photophobia (IFAP) syndrome (which is characterized by non-scarring alopecia), lichen planopilaris, and lichen spinulosus. IFAP syndrome is characterized by non-scarring alopecia in contrast to KFSD. The other two conditions can be also be differentiated by thorough clinic-pathological examination.[4911]

There is no specific treatment for KFSD. Various drugs have been tried to delay scarring alopecia such as isotretinoin and dapsone.[1011] For symptomatic relief emollients, topical steroid, and keratolytic agents can be used.