Skin nontumor
Alopecia
Dissecting cellulitis
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PubMed Search: Dissecting cellulitis
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Negative stains | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Zare P, Ramezani M. Dissecting cellulitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumordissectingcellulitis.html. Accessed June 29th, 2024.
Definition / general
- A neutrophilic scarring alopecia and member of follicular occlusion tetrad with the same histopathology
- Most cases present as an isolated disease
Essential features
- Fluctuating nodules on scalp, including occiput and vertex, leading to sinus tract formation
- One component of the follicular occlusion tetrad, which includes
- Hidradenitis suppurativa or acne inversa (axilla and groin)
- Acne conglobata (face)
- Pilonidal sinus (intergluteal fold)
- Dissecting cellulitis of scalp (vertex and occiput)
Terminology
- Dissecting cellulitis of scalp (DCS)
- Dissecting folliculitis
- Perifolliculitis capitis abscedens et suffodiens
- Hoffman disease
ICD coding
Epidemiology
- Mainly in young males of African ancestry but can affect any age and race (J Eur Acad Dermatol Venereol 2017;31:e199)
Sites
- Scalp
Pathophysiology
- Member of follicular occlusion tetrad: obstruction of the follicle with keratin plug, resulting in secondary rupture and inflammation (Clin Dermatol 2023;41:576, Clin Cosmet Investig Dermatol 2021;14:455)
Etiology
- Not completely understood
- Genetic and hormonal factors
- References: Clin Dermatol 2023;41:576, J Dermatol 2019;46:802
Clinical features
- Tender suppurative nodules with sinus tract formation
- Overlying patchy alopecia
- References: An Bras Dermatol 2020;95:514, Biomedicines 2021;9:1755
Diagnosis
- Physical examination and trichoscopy
- Skin biopsy
Prognostic factors
- Nodules wax and wane but untreated disease results in scarring alopecia (J Drugs Dermatol 2022;21:800)
Case reports
- 7 year old boy with dissecting cellulitis of scalp (Int J Trichology 2015;7:173)
- 18 year old man with tender multinodular lesions on the scalp (Arch Plast Surg 2020;47:631)
- 24 year old man with follicular occlusion triad (Postepy Dermatol Alergol 2023;40:176)
- 25 year old woman with dissecting cellulitis of scalp, initially misdiagnosed as infected trichilemmal cyst (Plast Reconstr Surg Glob Open 2021;9:e3661)
- 60 year old man presented with dissecting cellulitis of scalp following head trauma (Indian Dermatol Online J 2023;14:852)
Treatment
- Retinoids
- Systemic antibiotics
- Electron beam radiation
- 800 nm pulsed diode laser
- TNFα inhibitors
- Surgical intervention
- Reference: Dermatol Ther (Heidelb) 2023;13:2487
Clinical images
Images hosted on other servers:
Clinical stages of dissecting cellulitis of scalp
Microscopic (histologic) description
- Neutrophilic scarring alopecia
- Folliculitis
- Perifolliculitis
- Free hair shaft
- Follicular destruction
- Abscess formation
- Very dense inflammatory cell infiltrate
- Mixed inflammation: lymphocytes, neutrophils, plasma cells, histiocytes and eosinophils, predominance of plasma cells in some cases
- Inflammation heaviest towards the lower follicle
- Follicular fusion (compound folliculitis / tufting)
- Free (naked) hair shafts
- Deep granulation tissue and marked stromal edema
- Sinus tract formation
- Foreign body granulomatous reaction
- Perifollicular and interfollicular fibrosis
- Loss of sebaceous glands
- References: Actas Dermosifiliogr 2015;106:260, Int J Trichology 2015;7:107, Biomedicines 2021;9:1755, Histopathology 2010;56:24
Microscopic (histologic) images
Contributed by Pooria Zare, M.D., M.P.H., Mazaher Ramezani, M.D. and Kowsar Shekarbeigi, M.D.
Deep folliculitis
Perifolliculitis
Mixed inflammation
Abscess formation
Sinus tract
Follicular fusion
Negative stains
Sample pathology report
- Scalp (occiput), skin, biopsy:
- Deep folliculitis with sinus tract formation compatible with dissecting cellulitis of scalp (see comment)
- Comment: Mixed inflammation (lymphocytes, plasma cells, neutrophils and histiocytes) with folliculitis, abscess and sinus tract formation are in favor of diagnosis.
Differential diagnosis
- Folliculitis decalvans:
- Same histopathology as dissecting cellulitis of scalp except for absence of sinus tract formation and presence of more superficial follicular inflammation; less probable granulation tissue and edema
- Tinea capitis / kerion:
- Positive PAS diastase stain for fungal elements
- Pseudopelade of Brocq:
- End stage scarring alopecia
- May be considered end stage form of lichen planopilaris, discoid lupus erythematosus, dissecting cellulitis of scalp or other scarring alopecias
Additional references
Board review style question #1
A 30 year old man with a tender nodule on the occiput and discharge has undergone a skin biopsy. What is the most probable diagnosis according to histopathology and clinical presentation?
- Dissecting cellulitis of scalp
- Folliculitis decalvans
- Lichen planopilaris
- Pseudopelade of Brocq
Board review style answer #1
A. Dissecting cellulitis of scalp. Dissecting cellulitis of scalp shows mixed folliculitis and perifolliculitis with sinus tract formation mainly on the occiput and vertex. Answer B is incorrect because folliculitis decalvans presents the same histologic picture but without sinus tract formation. Meanwhile, the clinical presentation is mainly papules and pustules, not nodules. Answer C is incorrect because lichen planopilaris is mainly lymphocytic scarring alopecia without sinus tract formation. Answer D is incorrect because pseudopelade of Brocq is considered end stage scarring alopecia mainly after lichen planopilaris with no inflammation at presentation.
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Board review style question #2
Which one of the following diagnoses has a different histopathology from the others?
- Acne agminata
- Dissecting cellulitis of scalp
- Hidradenitis suppurativa
- Pilonidal sinus
Board review style answer #2
A. Acne agminata. Acne agminata or lupus miliaris disseminatus faciei has a tuberculoid-like granulomatous histopathology. Answers B, C and D are incorrect because these entities are members of follicular occlusion tetrad, along with acne conglobata.
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