🔍 Search
InfectionSurgicalICD-10 L02.x

Cutaneous abscess / furunculosis

Boil · furuncle · carbuncle (multiple coalescing) · skin abscess

A cutaneous abscess is a localised collection of pus within the dermis or subcutaneous tissue, most commonly caused by Staphylococcus aureus (including MRSA). A furuncle (boil) is a deep follicular abscess; a carbuncle is a coalescing group of furuncles. Management is principally incision and drainage (I&D); antibiotics are reserved for surrounding cellulitis, systemic features, immunosuppression and high-risk anatomy. UK antimicrobial decisions should follow NICE CKS for boils / carbuncles and NICE NG141 when cellulitis or erysipelas is present.

CurrentLast reviewed 18 May 2026
Clinical image of Cutaneous abscess / furunculosis
Cutaneous abscess / furunculosis. Image sourced from DermNet New Zealand. Used under CC BY-NC-ND 4.0. No endorsement implied.

Microbiology

  • Staphylococcus aureus — predominant; including community MRSA (PVL+ carriers).
  • Polymicrobial in anogenital / perineal / axillary settings; anaerobes (Bacteroides, Peptostreptococcus).
  • Hidradenitis suppurativa: chronic recurrent flexural abscesses; specialised pathway.
  • Risk factors: diabetes, obesity, immunosuppression, IV drug use, atopic eczema, S. aureus nasal carriage.

Clinical features

  • Tender, erythematous, fluctuant nodule with surrounding induration.
  • Spontaneous pointing / pustule formation common.
  • Sites: face, neck, axillae, groin, buttocks, thighs.
  • Furuncle: deep follicular abscess; commonly hair-bearing sites.
  • Carbuncle: cluster of communicating furuncles; deeper involvement; often diabetic / immunosuppressed; back of neck classic.
  • Hidradenitis suppurativa abscess: chronic; flexural; sinus tract formation.
  • Complications: cellulitis, lymphangitis, bacteraemia, sepsis, endocarditis (rare), facial / nasal-triangle thrombophlebitis.

Investigations

  • Clinical diagnosis usually adequate.
  • USS confirms collection if uncertain about fluctuance.
  • Pus swab on I&D for culture & sensitivity (especially MRSA screening, recurrent disease).
  • Nasal / axillary / groin swab if recurrent (S. aureus carrier).
  • Bloods (FBC, CRP, U&E, glucose) if systemic features or comorbid.
  • HIV, immunoglobulins for unusual / atypical recurrent abscesses.

Management

  • Incision and drainage (I&D) — primary intervention:
    • Local anaesthetic with adrenaline (or field block).
    • Incise along Langer lines / RSTL; ensure adequate drainage.
    • Pus swab for culture.
    • Loculation breakdown with finger / forceps.
    • Wound packing (hypertonic saline / Aquacel ribbon / iodoform gauze) for large cavities; daily change; alternatively loop drainage technique for thigh / buttock.
  • Antibiotics adjunct only if clinically indicated:
    • Surrounding cellulitis / extensive infection.
    • Systemic features (fever, malaise, raised inflammatory markers).
    • Immunosuppression, diabetes, comorbidity.
    • Recurrent disease.
    • Facial / perineal / hand abscess.
  • First-line oral: flucloxacillin 500 mg QDS for 5-7 days.
  • Penicillin-allergic: clarithromycin / erythromycin / doxycycline.
  • MRSA: doxycycline 100 mg BD, co-trimoxazole, clindamycin 300-450 mg QDS.
  • Recurrent disease:
    • Decolonisation: nasal mupirocin 2% BD × 5 days + chlorhexidine 4% body wash × 5-7 days.
    • Treat household members concurrently.
    • Address risk factors: BMI, smoking, glycaemic control.
  • Hidradenitis suppurativa: dedicated pathway; antibiotic (e.g. doxycycline / clindamycin + rifampicin), adalimumab / secukinumab; deroofing / excision.
  • Carbuncle: hospital admission for IV antibiotics in selected cases; surgical debridement.

References

  1. NICE Clinical Knowledge Summary. Boils, carbuncles, and staphylococcal carriage. London: NICE; accessed 18 May 2026.
  2. NICE NG141. Cellulitis and erysipelas: antimicrobial prescribing. London: NICE; 2019.
  3. Stevens DL et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections. Clin Infect Dis. 2014;59:e10-e52.
  4. Singer AJ, Talan DA. Management of skin abscesses in the era of methicillin-resistant Staphylococcus aureus. N Engl J Med. 2014;370:1039-1047.
  5. British Association of Dermatologists. UK guidelines for the management of hidradenitis suppurativa. Br J Dermatol. 2019;180:1009-1017.

Spot a correction?

If any clinical statement, citation or link on this page needs updating, please email admin@skinoncology.net with the page name, the proposed correction and the supporting source.