Dissecting cellulitis of the scalp
CLINICAL PRESENTATION
Dissecting cellulitis of the scalp (DCS) (also known as Hoffman’s disease or perifolliculitis capitis abscedens et suffodiens) was first described in 1903. (1, 2, 3) It is an uncommon, chronic destructive folliculitis and neutrophilic scarring alopecia of the scalp. It clinically characterized by painful nodules, drainage of puss, sinus tracts, keloid/ thick scar formation, and scarring alopecia (2, 4). It can also be associated with pain, itching and bad odor (5). It is part of the follicular occlusion tetrad that includes hidradenitis suppurativa and acne conglobate, pilonidal cysts (6, 7).
EPIDEMIOLOGY
DCS can affect men and women from all races and ethnicities, however, it most commonly affects black males between the ages of 20 and 40 (2, 8).
CAUSES
The exact cause of DCS is unknown. However, there have been some associated factors.
Follicular hyperkeratosis (thickened follicles) leads to the formation of plugs and follicle occlusion. The previously mentioned causes follicle rupture, intense inflammation and eventual scar formation (9)
Genetics: Autosomal dominant inheritance (10)
Trauma (2)
DIAGNOSIS
DCS is diagnosed via careful history, clinical scalp and hair exam, and dermoscopic evaluation (11, 12). Scalp biopsies may be performed to help confirm the diagnosis. Bacterial culture to rule out secondary bacterial infection.
CLINICAL IMITATORS (DIFFERENTIAL DIAGNOSIS)
Tinea capitis (scalp fungus), alopecic and aseptic nodules of the scalp, pseudopelade of Brocq, squamous cell carcinoma (skin cancer), metastatic Crohn’s disease, and erosive pustular dermatosis of the scalp (7)
ASSOCIATED CONDITIONS
Follicular unit tetrad: Hidradenitis suppurativa, acne conglobata, DSC , pilonidal cysts (2, 7)
Although abscesses in DCS are sterile, secondary bacterial infection (Staphylococcus, Pseudomonas, Peptostreptococcus. Propionibacterium species) can be found (7, 13) in DCS lesions.
It can also be associated with arthritis, keratitis, pyoderma gangrenosum, keratitis-ichthyosis-deafness syndrome, pilonidal cysts, and osteomyelitis, and Crohn’s disease (7, 8, 9, 13).
TREATMENT OPTIONS (2, 3, 7, 9)
Treatment of this disease is often difficult and is often resistant to multiple medical and surgical therapies. Frequent relapses are common after discontinuation of treatment. Treatments methods are often combined for maximal efficacy.
*Antibiotics: Ciprofloxacin, clindamycin (oral and topical), rifampin, and
*Tumor necrosis factor (TNF) inhibitors: Adalimumab, Infliximab (9, 14)
*Retinoids: Isotretinoin (15)
Other anti-microbials : Minocycline, trimethoprim/sulfamethaxole, doxycycline, azithromycin, amoxicillin/ clavulanate, fluconazole, clarithromycin, dapsone
Anti-Inflammatory: Steroids (oral/ topical/ injection),
Surgical: Incision and drainage, radical scalp removal (excision) with grafting (16, 17), carbon dioxide ablation of the scalp
Radiation (18)
Laser/ Light Therapy: Aminolevulinic acid-photodynamic therapy (ALA-PDT) (5, 19) Laser (694 nm, 800 nm, 1064nm)
Other: Colchicine, zinc sulphate, anti-androgens ( cyproterone acetate, ethinyl estradiol- (6)
(* Preferred - 7)