Topic 3: Distinguish HS From Common Mimickers
No single lesion proves HS. Diagnosis depends on compatible morphology, characteristic distribution, and chronicity or recurrence. Mimickers in adolescent patients should be considered in context.
| Condition | Features that may overlap | Clues favoring or questioning HS |
| Furuncle or bacterial abscess | Painful inflamed or draining nodule | A single event favors infection; repeated lesions in multiple intertriginous sites and characteristic scars favor HS |
| Folliculitis | Follicular papules or pustules | Usually more superficial; deep painful recurrence and tunnels are less typical |
| Inflamed epidermoid cyst | Tender subcutaneous nodule with drainage | Often solitary with a central punctum; repeated regional lesions suggest another process |
| Acne | Comedones, nodules, and scarring | Face, chest, and back predominate; intertriginous recurrence suggests HS, although both may coexist |
| Pilonidal disease | Painful draining disease near the gluteal cleft | Localized sacrococcygeal disease may occur alone or as part of a follicular-occlusion pattern |
| Cutaneous Crohn disease or perianal fistulizing disease | Perineal or perianal drainage and inflammation | Gastrointestinal symptoms, atypical ulcers, or fistula pattern should prompt broader evaluation and specialist coordination |
| Safety note: Fever, systemic illness, rapidly spreading erythema, severe disproportionate pain, immunocompromise, or concern for a deep perineal or perianal process requires evaluation for acute infection or another urgent diagnosis rather than assuming every lesion is an HS flare. |