# Acne Conglobata and Acne Fulminans > NEET-PG Dermatology notes on acne conglobata and acne fulminans, covering systemic features, steroid and isotretinoin treatment and contrast with vulgaris. - Canonical URL: https://prepelephant.com/topics/neet-pg/dermatology/acne-conglobata-and-fulminans - Exam / course: NEET-PG · Subject: Dermatology - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-15 - Last updated: 2026-10-15 - Reference basis: IADVL Textbook of Dermatology; Fitzpatrick's Dermatology; Rook's Textbook of Dermatology - How to cite: "Acne Conglobata and Acne Fulminans", PrepElephant, https://prepelephant.com/topics/neet-pg/dermatology/acne-conglobata-and-fulminans ## Direct answer Acne conglobata and acne fulminans are the most severe end of the acne spectrum, marked by deep, interconnected nodules and scarring. Conglobata is a chronic, sinus-forming disease without systemic upset, whereas fulminans starts abruptly with fever, joint pain and raised inflammatory markers. Systemic corticosteroids control fulminans, and isotretinoin is the long-term treatment for both. ## What you must remember - **Acne conglobata:** severe nodulocystic acne with communicating sinus tracts, abscesses and extensive scarring, typically on the back, chest, buttocks and face. - **Acne fulminans:** abrupt onset of ulcerated, haemorrhagic nodules with systemic features, classically in young men. - **Systemic features:** fever, malaise, arthralgia, leucocytosis and raised ESR and CRP separate fulminans from conglobata. - **Bone involvement:** fulminans may cause bone pain and lytic change, classically of the sternum and clavicles, which prompts imaging. - **Triggers:** isotretinoin is a recognised trigger, especially at the start of treatment, and anabolic steroid use is another association. - **Difference from acne vulgaris:** vulgaris ranges from comedones to nodules, whereas conglobata is defined by sinus tracts and abscesses that vulgaris does not form. - **Steroid role:** oral prednisolone is used in fulminans to suppress systemic inflammation and is tapered as the lesions settle. - **Isotretinoin role:** it is the cornerstone of conglobata and is restarted in fulminans only after the disease has settled, under specialist supervision. ## Stepwise approach to a severe acne patient A 19-year-old man has ulcerated chest nodules that developed over ten days, together with fever and knee pain. The steps below separate conglobata from fulminans and set the urgency of treatment. 1. **Document the lesions:** Record whether nodules are interconnected by sinus tracts, and whether they are ulcerated, haemorrhagic or abscessed. 2. **Ask about systemic symptoms:** Fever, malaise and joint pain point towards fulminans, and the joints and tender bones should be examined. 3. **Check recent drugs:** Ask about isotretinoin started in the past weeks and about anabolic steroid use, since either can be the trigger. 4. **Send baseline investigations:** A full blood count, ESR and CRP are measured, and imaging of the sternum and clavicles is considered when bone pain is present. 5. **Start systemic treatment for fulminans:** Oral prednisolone controls the inflammation, while antibiotics alone are inadequate for a systemic picture. 6. **Plan isotretinoin with monitoring:** Isotretinoin is the cornerstone for conglobata, with checks of lipids, liver enzymes and pregnancy status. In fulminans it is restarted only after the disease has settled, under specialist supervision. ## Where the exam tries to catch you Severe acne questions test the difference between conglobata and fulminans, and the urgency that systemic features demand. - **Trap:** treating acne fulminans as ordinary severe acne managed with antibiotics. **Correct:** the systemic features need prompt corticosteroids, because antibiotics do not control the inflammatory picture. - **Trap:** confusing acne conglobata with hidradenitis suppurativa. **Correct:** hidradenitis favours apocrine sites such as the axillae and groins, whereas conglobata favours the face, back, chest and buttocks. - **Trap:** restarting isotretinoin straight after fulminans. **Correct:** isotretinoin can be the trigger, so it is restarted only once the disease is quiet, with steroid cover and specialist review. ## Frequently asked questions ### Which laboratory findings favour acne fulminans over acne conglobata? Raised ESR and CRP and leucocytosis, together with fever and arthralgia, favour acne fulminans over acne conglobata. Bone pain with lytic change on imaging supports the same diagnosis, as systemic inflammation is the defining feature of fulminans. ### Why is isotretinoin a concern in acne fulminans? Isotretinoin has been reported to trigger acne fulminans, particularly when it is started, so the drug is stopped at the onset of fulminans. Restarting isotretinoin requires that the inflammation has settled and that a specialist has reviewed the patient. ### What is the role of systemic corticosteroids in acne fulminans? Systemic corticosteroids, usually oral prednisolone, suppress the systemic inflammation and rapidly reduce the ulcerative lesions of acne fulminans. They are tapered as the disease settles, because they do not cure the underlying acne. ### How does acne conglobata differ from acne vulgaris? Acne vulgaris is graded from comedones to nodules, but acne conglobata is defined by interconnected sinus tracts, abscesses and extensive scarring. Conglobata also has a predilection for the back, chest and buttocks, and it usually needs isotretinoin rather than topical therapy alone.