Perforating folliculitis in Down’s syndrome − a rare case report
Aswath Rajan, Varadraj Vasant Pai, Pankaj Shukla
Department of Skin (DVL), Goa Medical College, Goa, India
Correspondence Address:
MD (Skin) Aswath Rajan
Department of Skin (DVL), Goa Medical College, 633c, Thirumalai Nagar, Near TSP Camp, Palani 624601, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ejdv.ejdv_60_20
Perforating folliculitis is a primary perforating disorder, characterized by the phenomenon of transepidermal elimination. It is associated with various disorders such as psoriasis, juvenile acanthosis nigricans, diabetic mellitus, renal failure, cardiac failure, and malignant neoplasia. Other primary perforating dermatoses are Kyrle’s disease, reactive perforating collagenosis, and elastosis perforans serpiginosa. Among the association of perforating dermatoses with genetic diseases like Down’s syndrome, elastosis perforans serpiginosa and very rarely reactive perforating collagenosis have been reported. We report the first case of an 11-year-old boy who is a known case of Down syndrome presented with perforating folliculitis.
Keywords: dermoscopy, Down syndrome, perforating folliculitis, transepidermal elimination
Perforating dermatosis is a heterogeneous group of disorders characterized by transepidermal elimination of dermal components such as collagen, elastin, or fibrin. The extruded material may also include red cells, inflammatory cells, pathogens, and extracellular substances such as mucin or altered connective tissue components [1]. Primary perforating disorders include the subtypes such as Kyrle’s disease, perforating folliculitis, reactive perforating collagenosis, and elastosis perforans serpiginosa that occur owing to a defect in epidermal keratinocytes, hair follicles, and collagen and elastic fibers, respectively [2]. Among the perforating dermatoses, elastosis perforans serpiginosa and a very rarely reactive perforating collagenosis are associated with Down’s syndrome [3],[4]. Here, we present the first case report of perforating folliculitis in association with Down’s syndrome.
Case reportHistory
An 11-year-old boy who was a known case of Down’s syndrome presented to skin outpatient department with history of skin lesions on left leg for 6 months, associated with itching. The patient gave history of accidental fall from height 6 months back and was diagnosed with fracture shaft of femur, following which the plaster cast was applied over left lower limb for continuous 3 months. After removal of the cast, the patient’s mother noticed skin lesions over the covered areas that gradually extended to other leg, buttock, and lower abdomen over the period of 6 months ([Figure 1]).
Figure 1 Clinical image showing involvement of bilateral lower limb, extending from the legs, thigh, gluteal region, and the lower abdomen, more on the extensors.On examination, there was involvement of bilateral lower limb, extending from the legs, thigh, gluteal region, and the lower abdomen, more on the extensors in the form of multiple discrete folliculocentric papules, around 2–8 mm in diameter with small central keratotic plugs ([Figure 2]).
Figure 2 Magnified view of a clinical image showing discrete papules with central keratotic plugs and follicular orientationDermoscopic imaging revealed several features that gave insight to both the underlying pathology and histology. The orange-brown clod in the center of the lesions corresponded to a dilated infundibulum stuffed with intraepidermal nest of keratin and extruded cell debris ([Figure 3]). Most of the clod had a coiled-up hair at the center of the lesion (U-shaped hair and coiled hair). In some lesions, gentle removal of scales helped in better visualization of trapped hair ([Figure 4]). The structureless gray-white area surrounding the central brown clod is most probably a consequence of the combination of epidermal changes (para and orthokeratosis, hypergranulosis, and pseudoepitheliomatous hyperplasia) and dermal changes (thickened bundles of collagen in vertical orientation). The other possible reason for the gray-white halo is the hair follicles plunge underneath the dermis at an angle to the skin surface, so the debris in the follicles which also contains melanin, gives blue-white color owing to Tyndall effect. Some of the newly formed papules showed ill-defined orange-brown clod with tuft of hair follicles arising from it ([Figure 5]).
Figure 3 Dermoscopic image showing orange-brown clod with coiled-up hair at the center of the lesion (U-shaped hair) (Heine delta T20 dermoscopy − ×10 image).Figure 4 Dermoscopic image showing orange-brown clod with structureless gray-white area halo and scaling. Better visualization of trapped hair after removal of scales (inlet) (Heine delta T20 dermoscopy − ×10 image).Figure 5 Dermoscopic image from the newly developing lesion showing poorly developed brown clod with tuft of hair follicles (Heine delta T20 dermoscopy − ×10 image).A two 4-mm dermoscopic-guided punch biopsy was taken. One from the lesion showing well-developed brown clod with trapped hair and the other from the new lesions with poorly developed clod with tuft of hair. Well-developed old lesions showed parakeratotic plug with neutrophils, and underlying epidermis showing a widely dilated follicular infundibulum filled with keratin, parakeratotic, orthokeratotic materials, basophilic debris, and few inflammatory cells ([Figure 6]). The follicular epithelium showed mild pseudoepitheliomatous hyperplasia extending into the corium. The corium shows foci of degenerative of dermal connective tissue in connection with areas of perforation ([Figure 7]). The newer lesions showed mild parakeratosis, acanthosis, perifollicular infiltration, and multiple transepithelial channels with extrusion of inflammatory cells ([Figure 8]).
Figure 6 Histopathological image (×10) showing mild parakeratosis. Acanthosis underlying epidermis showing a widely dilated follicular infundibulum filled with keratin, parakeratotic, orthokeratotic materials, basophilic debris, and few inflammatory cells. (inlet-dermoscopic image of HPE section). HPE, histopathological.Figure 7 Histopathological image (×40) showing dilated follicular infundibulum, with corium showing foci of degenerative of dermal connective tissue in connection with areas of perforation.Figure 8 Histopathological image (×10) of newer lesions showing mild parakeratosis, acanthosis, perifollicular infiltration, and multiple transepithelial channels with extrusion of inflammatory cells (inlet-dermoscopic image of HPE section). HPE, histopathological.Blood analysis including complete hemogram, liver and renal function test, and urine analysis was found to be normal. The diagnosis of perforating folliculitis was made based on dermoscopic and histological report.
DiscussionTransepidermal elimination is the phenomenon in which material from the dermis is extruded to the exterior through the epidermal channel with little or no disruption of the surrounding structures. Primary transepidermal elimination disorders are Kyrle’s disease, perforating folliculitis, reactive perforating collagenosis, and elastosis perforans serpiginosa. It is also seen as a secondary phenomenon in various dermatoses such as perforating granuloma annulare, pseudoxanthoma elasticum, keratoacanthoma, and chondrodermatitis nodularis helicis [5]. Among the primary disorders, perforating folliculitis was first described by Mehregan and Coskey in 1968. It is a relatively uncommon disorder affecting both men and women in their second to fourth decade as multiple follicular papules with central keratotic plug. The lesion may last for a month to years with the periods of remission and relapses. Mehregan and Coskey [6] also noted a curled-up hair within the area of perforation in most of the cases, and hence abnormal follicular keratinization caused by mechanical disruption is thought to play a role in the pathogenesis. The lesions are more common on the extensor surfaces of the extremities that are more prone for friction [6]. The chronic friction initiates the abnormal keratinization within the follicular infundibulum that eventually leads to perforation and exposing the follicular content to the dermis. The resulting inflammatory and necrotic material is then eliminated through the perforating canal by means of transepidermal elimination [7]. Trapping of the hair may fasten this process. However, such hairs are not always found even after careful sectioning but can be visualized on dermoscopy.
Among the transepidermal elimination disorders, elastosis perforans serpiginosa is closely associated with heritable disorders of connective tissue such as Down’s syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, and Marfan syndrome [2]. The connective tissue dysplasia seen in the form of hyperlaxity, premature ageing, and acrocyanosis in Down’s syndrome could be a potential explanation for abnormal elastic tissue that is extruded through the epidermis. This thickened coarse elastic fibers act a foreign body triggering the formation of narrow transepithelial channels for elimination. EPS presents as erythematous coalescent keratotic papules and are typically annular, that is, an arcuate or serpiginous rim with central clearing. The localized form is mostly idiopathic commonly seen on the nape of the neck, face, trunk, upper limb, and lower limb, whereas the generalized form is associated with the Down’s syndrome [8],[9].
Berker et al. [4] reported a case of reactive perforating collagenosis (RPC) in association with Down’s syndrome with lupoid hepatitis. RPC is characterized by the transepidermal elimination of focal damaged collagen, clinically present as umbilicated papules filled with keratinous plugging. On histopathology, the disrupted collagen with inflammatory cells and keratinous debris is seen extruding through the cup-shaped epidermal depression.
Various treatment options available for perforating folliculitis are topical and intralesional corticosteroids, topical retinoids, and keratolytic agents, such as urea and salicylic acid. Oral histamines and emollients are usually prescribed for itching. Few case reports show successful treatment with oral retinoids, tetracyclines, phototherapy, and allopurinol [10].
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