Clinical outcomes of adalimumab treatment in dissecting cellulitis, along with pre- and post-treatment trichoscopic findings: A retrospective, multicentre study of 29 cases

Dissecting cellulitis (DC) is a rare, chronic neutrophilic cicatricial alopecia characterized by nodules, abscesses, sinus tracts, and scarring.1 Pathophysiology of DC remains vague, but exaggerated tumor necrosis factor-alpha-mediated immune response has been proposed, making adalimumab a promising therapeutic option.2

This multicentre retrospective study evaluates the clinical response to adalimumab in 29 patients with DC treated between 2010 and 2024. Inclusion criteria were individuals diagnosed with DC, treatment with adalimumab (hidradenitis suppurativa or psoriasis dosing scheme), and ≥16-week follow-up period.

Therapeutic outcomes were assessed at a maximum of 20 weeks based on reduction in inflammatory lesion count (nodules, suppuration), decrease in pain, via Numeric Rating Scale, quality of life (QoL), using Dermatology Life Quality Index, Physician Global Assessment tool, occurrence of adverse events and trichoscopic findings. Complete response (no inflammatory lesions and new scarring), and partial response (mild inflammation without new scarring) were additionally evaluated. Descriptive statistics, t-test, and chi-square test were performed (SPSS v.21.0) with significance at P value <.05. Results were adjusted for potential confounding variables, including the duration of adalimumab treatment and concomitant medications. Ethical approval was waived for this study.

Demographics are presented in Table I. Mean treatment duration was 20.1 (±12.4) months. Complete response and partial response were achieved by 17.2% (5/29) and 48.3% (14/29) of patients, respectively (Table II, Supplementary Fig 1, available via Mendeley at https://data.mendeley.com/datasets/8834zgzydc/1.). Inflammatory nodules significantly decreased (8.0 (±5.4) to 3.0 (±2.3); P < .00), alongside Physician Global Assessment scores (3.0 (±0.9) to 1.0 (±0.8); P < .001) and suppuration (2.0 (±1.0) to 1.0 (±0.9); P = .00). Decreased suppuration, pain relief, and disfigurement improvement directly correlated with enhanced patients' QoL, since Dermatology Life Quality Index (17.0 (±3.9) to 4.0 (±2.5); P < .001) and pain Numeric Rating Scale (7.0 (±2.3) to 2.0 (±1.6); P < .001) greatly improved. No adverse events were reported.

Table I. Patients' demographics and characteristics of dissecting cellulitis

Suppuration: 0-absent; 1-mild; 2-moderate; 3-severe.

DC, Dissecting cellulitis; SD, standard deviation.

Table II. Adalimumab treatment characteristics, efficacy, and safety

Suppuration: 0-absent; 1-mild; 2-moderate; 3-severe.

CI, Confidence interval; DC, dissecting cellulitis; DLQI, Dermatology Life Quality Index; NRS, Numeric Rating Scale; PGA, Physician Global Assessment; SD, standard deviation.

∗

P < .05 is considered statistically significant (Italics).

Trichoscopy revealed notable post-treatment improvement: reduced broken hairs [89.7% (26/29) to 20.7% (6/29); P < .001], yellow dots [69.0% (20/29) to 34.5% (10/29); P < .001], black dots [75.9% (22/29) to 44.8% (13/29); P = .04], peri- and inter-follicular scaling [75.9% (22/29) to 27.6% (8/29) (P < .001], pustules and structureless yellow areas [44.8% (13/29) to 6.9% (2/29); P < .001] (Supplementary Fig 1, available via Mendeley at https://data.mendeley.com/datasets/8834zgzydc/1.). Erythema also improved [69.0% (20/29) to 24.1% (7/29); P < .001]. However, follicular loss or scarring persisted [65.5% (19/29) to 62.1% (18/29); P = 1.00], which conforms with the cicatricial nature of advanced DC.

Our findings indicate that adalimumab is highly beneficial in reducing inflammation, inhibiting follicular destruction, and substantially improving the QoL in patients with DC.3, 4, 5 As part of the follicular occlusion tetrad, DC is both physically debilitating and psychologically distressing, considering the patients' young age and the cicatricial nature of the disease.4

Adalimumab seems to mitigate acute symptoms and curtail disease progression. Clinical improvement underscores its therapeutic potential, while trichoscopic findings indicate efficient suppression of inflammation. The persistence, nonetheless, of structural damage highlights the need for early intervention before irreversible scarring occurs.

Moreover, given the stigma and social burden associated with DC-related disfigurement, achieving disease control can enhance the self-esteem and QoL of the affected individuals.1

While promising, these results are limited by the retrospective design, male-only participant and small sample size. Larger trials are warranted to assess long-term outcomes.