ABSTRACT- 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. Being X-linked it is more common in males but rarely, can be seen in females. We report this rare disorder in siblings affecting both male and female child.
Key-words- Keratosis follicularis spinulosa decalvans, Siblings, scarring alopecia, Child, Keratotic papules

INTRODUCTION
Keratosis pilaris atrophicans is a broad term encompassing three rare and distinct clinical entities including keratosis pilaris atrophicans faciei (KPAF), atrophoderma vermiculata and keratosis follicularis spinulosa decalvans. Common to these conditions are keratotic follicular papules, non-purulent inflammation of variable degree and atrophic end stages characterized by irreversible hair loss and/or atrophic depressions similar to pitted scars.it has X- linked inheritance however cases have also been seen in families suggesting autosomal dominant pattern of inheritance [1]. Very few cases of KFSD have been reported in Indian literature. We hereby present a case report of KFSD, a rare cause of scarring alopecia in siblings.

CASE REPORT
Three year old male child born prematurely at 7 month of gestation period presented with history of absence of scalp and eyebrow hair since birth and rough skin over scalp since 2 years. At birth, parents noticed absence of scalp and eyebrow hair. After 1 year of age fine, brittle and scanty hairs appeared.
On physical examination multiple follicular, skin coloured keratotic papules were present on scalp (Fig. 1) and extensor aspect of bilateral arms. Hairs on scalp were sparse, short and brittle with areas of scarring alopecia (Fig. 2).
Eyebrows and eyelashes were also sparse. Teeth, nails, palms and soles were found to be normal. There was no history of photophobia and ophthamological examination revealed no abnormal findings. His younger sister 2 year old of age had similar complaints. She also had similar lesions over scalp with loss of scalp and eyebrow hairs (Fig. 4). Parents were unaffected.
Hair microscopy and dermoscopy of scalp hair was done to rule out monilethrix and found to be normal. Punch biopsy was taken from male child but not from his younger sibling. Histopathological examination revealed dilation of follicular infundibulum and plugging with orthokeratotic corneocytes with some others showing mild spongiosis. Few follicles in deep dermis showed dense perifollicular fibroplasia and sparse superficial perivascular and periappendageal lymphocytic infiltrate (Fig. 5 & 6). Based on above clinical feature, family history and histopathology diagnosis of keratosis follicularis spinulosa decalvans was made.
Our patient was started on 0.5 mg/kg of isotretinoin and topical retinoic acid 0.025%at night time. Lesions on body were treated with retinoic acid at night and urea containing moisturizers at day time. After 2 months patient had improvement in terms of increased hair growth and absence of disease progression (Fig. 3). Follicular lesions softened but persisted. He was asked to continue same treatment and come back for review in a month time.

Figure 1: Multiple skin coloured keratotic follicular
papules with sparse hair


Figure 2: Follicular papules with areas of Scarring
alopecia before starting treatment




Fig. 3: After 1 month of giving isotretinoin therapy



Fig. 4: Siblings with Sparse hair and Follicular keratotic papules



Fig. 5



Fig. 6
Fig. 5 & 6: Dilation of follicular infundibulum and
plugging with orthokeratotic corneocytes. Few follicles
in deep dermis showed dense perifollicular fibroplasia
and sparse superficial perivascular and
periappendageal lymphocytic infiltrate

DISCUSSION
Keratosis follicularis spinulosa decalvans is a rare genetic disorder first described by Macleod however descriptive term was first used by Siemens in 1926 ^[2]. It has X-linked dominant mode of inheritance mapped to chromosome Xp 22.13- p 22.2. The candidate gene suggested is the membrane-bound transcription factor protease site 2 (MBTPS2) genes 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 [3]. This condition affects predominantly males with females being carriers showing no disease or only mild forms. The process of lyonization (non –random X inactivation) may explain expression of KFSD in women. However cases have also been seen in families suggesting autosomal dominant inheritance [1]. In present case report, both brother and sister are affected without any other family members being involved. They may either have X-linked dominant inheritance with process of lyonization explaining the manifestations in sister or autosomal dominant pattern of inheritance with variable penetrance.
The condition begins in infancy with follicular keratosis on nose and cheeks and then on scalp, eyebrows, neck and body. Scarring alopecia of eyebrows and scalp begins in early childhood and progresses till puberty. Associated features include palmoplantar keratoderma, with predilection for calcaneal region, high periungual cuticles ^[4]. The ocular abnormalities include photophobia, keratitis, conjunctivitis, congenital glaucoma and lenticular cataract ^[5].
The differential diagnosis of KFSD includes ichthyosis follicularis alopecia, photophobia syndrome, lichen planopilaris and lichen spinulosa. IFAP syndrome is characterized by non-scarring alopecia in contrast to KFSD. The other two conditions can be differentiated by thorough clinic-pathological examination ^[2]/.
Treatment of KFSD is usually unsatisfactory. Topical treatment comprises mainly of keratolytics and emollients ^[1]. 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 ^[7]. Other treatments tried include antibiotics, intralesional and topical steroids. Hair reduction lasers have also been tried ^[8].

CONCLUSION
It is a rare cause of scarring alopecia affecting both brother and sister. Very few cases of Keratosis follicularis spinulosa decalvans have been reported in Indian literature especially in females.

REFERENCES

1. Sequeira FF, Jayaseelan E. Keratosis follicularis spinulosa decalvans in a female. Indian J Dermatol Venereol Leprol. 2011; 77:325–7.
2. Maheswari UG, Chaitra V, Mohan SS. Keratosis follicularis spinulosa decalvans: a rare cause of scarring alopecia in two young Indian girls. Int J Trichology. 2013; 5(1):29-31.
3. Fong K, Wedgeworth EK, Lai-Cheong JE, Tosi I, Mellerio JE, Powell AM, et al. MBTPS2 mutation in a British pedigree with keratosis follicularis spinulosa decalvans. Clin Exp Dermatol. 2012; 37:631–4.
4. Van Osch LD, Oranje AP, Keukens FM, van Voorst Vader PC, Veldman E. Keratosis follicularis spinulosa decalvans: A family study of seven male cases and six female carriers. J Med Genet. 1992; 29:36-40.
5. Rand R, Baden HP. Keratosis follicularis spinulosa decalvans- Report of two cases and literature review. Arch Dermatol. 1983; 199:22-6.
6. Richard G, Harth W. Keratosis follicularis spinulosa decalvans. Therapy with isotretinoin and etretinate in the inflammatory stage. Hautarzt. 1993; 44:529-34.
7. Kunte C, Loeser C, Wolff H. Folliculitis spinulosa decalvans: Successful therapy with dapsone. J Am Acad Dermatol. 1998; 39:891–3.
8. Chui CT, Berger TG, Price VH, Zachary CB. Recalcitrant scarring follicular disorders treated by laser-assisted hair removal: A preliminary report. Dermatol Surg. 1999; 25: 34–7.

International Journal of Life-Sciences Scientific Research (IJLSSR) Open Access Policy Authors/Contributors are responsible for originality, contents, correct references, and ethical issues. IJLSSR publishes all articles under Creative Commons Attribution- Non-Commercial 4.0 International License (CC BY-NC). https://creativecommons.org/licenses/by-nc/4.0/legalcode