Derm Cases · Dermatology / Infectious Diseases / General Practice
OSCE — boils and carbuncles: spectrum management and Staph decolonisation
An 8-minute OSCE station on the folliculitis–furuncle–carbuncle spectrum, incision and drainage principles, antibiotic stewardship, danger-triangle facial lesions, and recurrent furunculosis decolonisation.
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Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on the folliculitis–furuncle–carbuncle spectrum, incision and drainage principles, antibiotic stewardship, danger-triangle facial lesions, and recurrent furunculosis decolonisation.
Brief (to candidate)
A 31-year-old man has a large, tender, multi-headed boil on the nape of the neck with surrounding cellulitis and low-grade fever. He reports three similar “boils” on the buttocks in 6 months. A household member also gets boils. You have 8 minutes to classify the lesion, treat today, and prevent recurrence.
Candidate instructions
- Place the lesion on the folliculitis → furuncle → carbuncle spectrum.
- Prioritise incision and drainage when indicated.
- Choose antibiotics judiciously and identify red-flag sites.
- Plan work-up for recurrent furunculosis.
- Counsel decolonisation and hygiene for patient and close contacts.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Spectrum | Folliculitis: superficial follicular pustules; furuncle: deep painful nodule of one follicle; carbuncle: coalescent multiloculated abscess with multiple draining points, often neck/back, systemic symptoms more likely[1] |
| Microbiology | Usually S. aureus (± MRSA); consider Gram-negative/Pseudomonas in hot-tub folliculitis; eosinophilic folliculitis in advanced HIV is a different entity |
| Acute Rx | I&D is primary therapy for fluctuant furuncle/carbuncle; culture pus if recurrent/severe/MRSA risk; antibiotics if cellulitis, fever, facial danger zone, immunocompromise, or incomplete drainage[1][5] |
| Red flags | Danger triangle of face (cavernous sinus thrombosis risk); rapid spread; necrotising features; bacteraemia; diabetes uncontrolled |
| Recurrence | Seek triggers: carriage (nares/perineum), diabetes, obesity, crowding, shared fomites, PVL-associated clusters; avoid endless short antibiotics alone[2] |
| Decolonisation | Consider intranasal mupirocin + chlorhexidine body washes (and household measures) for recurrent culture-proven S. aureus furunculosis per local protocol; treat concurrent household cases when indicated[3][4] |
| Communication | Wound care, when to return (fever, spreading erythema), and why drainage beats antibiotic-only for abscess |
Model key actions
- Classify as carbuncle (multi-headed deep abscess) with surrounding cellulitis.[1]
- Incise and drain, culture if indicated, add systemic antibiotics for systemic/cellulitic disease.[1]
- For recurrent disease, plan S. aureus decolonisation and household hygiene measures.[2][3][4]
Common errors
- Antibiotics without drainage of a fluctuant abscess.
- Missing facial danger-triangle risk.
- No plan for recurrent disease or household transmission.
- Confusing with HS (chronic tunnels in axilla/groin) or simple acne.
- Ignoring possible MRSA in recurrent community clusters.
References5ShowHide
- [1]Lin HS, Lin PT, Tsai YS, et al. Interventions for bacterial folliculitis and boils (furuncles and carbuncles). Cochrane Database of Systematic Reviews, 2021.PMID 33634465
- [2]Ibler KS, Kromann CB. Recurrent furunculosis - challenges and management: a review. Clinical, cosmetic and investigational dermatology, 2014.PMID 24591845
- [3]Sharara SL, Maragakis LL, Cosgrove SE. Decolonization of Staphylococcus aureus. Infectious disease clinics of North America, 2021.PMID 33303331
- [4]Piewngam P, Otto M. Staphylococcus aureus colonisation and strategies for decolonisation. The Lancet. Microbe, 2024.PMID 38518792
- [5]David MZ, Daum RS. Treatment of Staphylococcus aureus Infections. Current topics in microbiology and immunology, 2017.PMID 28900682