Acne Conglobata of the Scalp.

Acne conglobata (AC) is a rare form of severe and chronic nodulocystic acne. It is characterized by nodulocystic lesions, borrowing, interconnecting abscesses, scars, in addition to grouped comedones. AC usually appears on the trunk and may extend to the buttocks. It can also appear, to a lesser extent, on the face, neck, shoulders, proximal arms, abdomen, and thighs. To the best of our knowledge, AC of the scalp has not been reported in the literature. Herein, we are reporting a case of AC of the scalp, emphasizing its clinical and trichoscopic features and how to differentiate it clinically from similar scalp conditions, especially alopecic and aseptic nodules of the scalp and dissecting cellulitis of the scalp. Copyright:

INTRODUCTION

Acne conglobata (AC) is a rare, chronic, and severe form of acne, first described by Lang in 1902 and Spitzer in 1903.[1],[2],[3] It is characterized by nodulocystic lesions, draining sinuses, interconnecting deep-seated abscesses with seropurulent discharge, grouped and polyporous comedones, and atrophic or hypertrophic scars.[3] Systemic symptoms are usually absent. It occurs mainly in young males and is usually located on the back, chest, or buttocks. It can also appear on the forehead, cheeks, neck, shoulders, upper arms, abdomen, and thighs.[3] To the best of our knowledge, AC of the scalp has not been reported in the literature.

CASE REPORT

A 23-year-old Iraqi male presented in our outpatient clinic at Al-Sadr Teaching Hospital with a 9-month history of nodular scalp lesion on the vertex accompanied by multiple scars and blackheads. The patient had recurrent episodes of the same lesion, which usually appeared as single or multiple nodules, enlarging in size to reach 2–3 cm in diameter, accompanied by the hair loss on the surface, and when resolved, leaving areas of scarring or nonscarring alopecia, with regrowth often occurs within 2–3 months. Puncture of the nodule usually reveals seropurulent material. The patient has a history of acne vulgaris controlled with oral isotretinoin. There were no other skin conditions or joint pain. Systemic symptoms were absent.

Examination of the patient's scalp showed a fluctuating, skin-colored, and dome-shaped nodule, 2 cm in diameter, on the vertex, accompanied by hair loss on the surface, with regrowth of a few hairs. There were also multiple atrophic scars and three areas of alopecia, 1–2 cm in diameter, resulting from resolved nodules. A close observation of the scalp showed multiple grouped comedones distributed over the vertex and occipital areas [Figure 1].

Figure 1

Superior view of the patient's scalp shows a dome-shaped nodule with multiple atrophic scars and comedones. Note the multiple grouped comedones (inset)

Trichoscopic examination of the nodule revealed a honeycomb pattern, black dots, white dots, vellus hairs, broken hair shafts, and violaceous areas [Figure 2a]. Trichoscopy of other vertex and occipital areas showed multiple grouped comedones [Figure 2b].

Figure 2

(a) Trichoscopy of the nodular lesion reveals a honeycomb pattern, few black dots, white dots, vellus hairs, broken hair shafts, and violaceous areas. (b) Trichoscopy of the vertex and occipital areas shows multiple grouped comedones

A biopsy from the nodule showed follicular plugging, ruptured pilosebaceous apparatus with mixed inflammatory infiltrate (perifollicular and in the deep dermis) [Figure 3]. Cultures of the punctured material were negative. The patient tried oral isotretinoin without improvement. However, new lesions have not developed after 2 months of treatment with oral doxycycline, 100 mg/day, with improvement of the already presented lesions.

Figure 3

Histopathology shows ruptured pilosebaceous unit with perifollicular mixed inflammatory infiltrate, (H and E; ×4). Note the mixed inflammatory infiltrate (inset, ×40)

DISCUSSION

AC occurs usually as nodulocystic lesions on the back, chest, or buttocks. It can less commonly be located on the face, neck, shoulders, upper arms, abdomen, or thighs.[3],[4],[5],[6],[7] Herein, we are reporting a case of AC located on the scalp. Other diseases that affect the scalp and present as nodulocystic lesions must be differentiated from AC of the scalp, in particular, alopecic and aseptic nodules of the scalp (AANS) and dissecting cellulitis of the scalp (DCS). AANS carry a good prognosis and may even resolve spontaneously or after treatment. It can be differentiated clinically from AC of the scalp by the absence of the scars or scarring alopecia. Comedones are usually absent in AANS. DCS and AC can be parts of a follicular occlusion tetrad, along with hidradenitis suppurativa and pilonidal sinus.[8] Grouped comedones are absent in DCS, and the trichoscopic examination usually shows yellow structureless areas and three-dimensional yellow dots over a dystrophic hair shaft, especially in the late stage of the disease.[9] These findings are absent in cases of AC of the scalp.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.