# Granuloma Annulare > Granuloma annulare in NEET-PG Dermatology: annular dermal papules without scale, palisading granulomas with mucin, subtypes and associations. - Canonical URL: https://prepelephant.com/topics/neet-pg/dermatology/granuloma-annulare - Exam / course: NEET-PG · Subject: Dermatology - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Granuloma Annulare", PrepElephant, https://prepelephant.com/topics/neet-pg/dermatology/granuloma-annulare ## Direct answer A ring of firm dermal papules with a perfectly normal surface — no scale, no vesicle — is granuloma annulare (GA) until microscopy says otherwise: a benign, usually asymptomatic dermatosis of grouped papules arranged in an annulus or arc, classically on the dorsa of hands and feet of children and young adults. Its two diagnostic signatures are negative — the ring carries no epidermal change, no scale, no vesicle — and histological: foci of necrobiotic (altered) collagen surrounded by palisaded histiocytes with abundant dermal mucin, i.e. a palisading granuloma. Localised GA (about three-quarters of cases) is self-limiting, resolving without scarring in months to years; generalised GA, with dozens of papules and plaques on trunk and extremities of older adults, is chronic and carries recognised associations with diabetes mellitus, dyslipidaemia and thyroid disease. Treatment is optional and symptomatic: potent topical or intralesional corticosteroids, cryotherapy, and for widespread disease phototherapy. ## What you must remember - **The ring without scale:** annular dermal papules with an entirely normal epidermal surface distinguish GA from tinea corporis (active scaly edge, KOH positive) — the commonest clinical confusion. - **Histology that names itself:** palisading granulomas around necrobiotic collagen with alcian-blue-positive mucin; no caseation (that is tuberculosis) and no naked granulomas (that is sarcoidosis). - **Subtypes:** localised (~75%, dorsa of hands and feet), generalised (older patients, metabolic associations), perforating (hands, papules with central crust exuding degenerate collagen), patch type (red-brown patches), subcutaneous (deep nodules on limbs of children — "pseudorheumatoid nodules", rheumatoid factor negative). - **Metabolic associations:** generalised GA warrants screening for diabetes mellitus, dyslipidaemia and thyroid dysfunction — an exam-quoted, guideline-acknowledged convention though causality is debated. - **Course:** localised disease resolves spontaneously in a large proportion of patients within two years; lesions may leave transient hypopigmentation but never scar. - **Treatment ladder:** no treatment is a legitimate option; then high-potency topical corticosteroid under occlusion, intralesional triamcinolone acetonide 5-10 mg/mL into the active edge, cryotherapy; generalised disease — narrowband UVB or PUVA. - **Rarer but examinable:** disseminated perforating GA in renal dialysis patients and HIV-associated GA; patch-type GA on sun-exposed skin mimicking actinic damage. - **Differential anchors:** tinea (scale, KOH), annular lichen planus (Wickham striae, itch), erythema annulare centrifugum (trailing inner scale), necrobiosis lipoidica (yellow-brown plaque with telangiectasia and atrophic shiny surface, shins, diabetic). ## From the clinic bench: reading the ring A 16-year-old shows you a smooth, skin-coloured ring on the back of the right hand that has grown outward over six months; it does not itch, and scraping has produced nothing at two pharmacies. You press a glass slide: the papules do not blanch away entirely (they are dermal). KOH from the edge is negative — with no scale there was little to scrape — and the arc of firm dermal papules with a normal surface clinches localised GA. You explain the natural history: most rings flatten by themselves, treatment is cosmetic, and intralesional triamcinolone 5 mg/mL into the advancing papules is the most reliable option. The subcutaneous variant deserves a separate mental slot: a firm, deep nodule on a child's pretibial skin or scalp looks exactly like a rheumatoid nodule, but the child has no arthritis and a negative rheumatoid factor — biopsy shows the same palisading granuloma deeper in the dermis. The second consultation is the one that changes management: a 58-year-old with a hundred firm papules and annular plaques across trunk, arms and legs. Generalised GA reframes the visit from skin to metabolism — fasting glucose or HbA1c, lipid profile and thyroid function are ordered. The skin itself is approached with narrowband UVB phototherapy over several months; recalcitrant cases have been reported to respond to tumour necrosis factor inhibitors and, in recent literature, JAK inhibitors, but phototherapy plus metabolic correction is the defensible exam answer. ## Where candidates slip The predictable error is calling a scaly ring "granuloma annulare" — GA never has an active scaly edge, and the KOH examination exists precisely to catch the impersonator. The reverse error is forgetting necrobiosis lipoidica in the shin-plaque stem: yellow-brown atrophic plaques with telangiectasia on a diabetic's shins are necrobiosis lipoidica, not GA, and they ulcerate. Histology questions contrast the palisading-with-mucin of GA against the caseating granuloma of tuberculosis and the "naked" non-caseating epithelioid granulomas of cutaneous sarcoidosis. A final viva question asks whether GA needs systemic work-up: only the generalised subtype justifies metabolic screening — localised disease does not. ## Frequently asked questions ### How is granuloma annulare differentiated from tinea corporis? GA is a ring of dermal papules with no scale, no epidermal change and a negative KOH, whereas tinea has an active scaly advancing edge and hyphae on microscopy. ### What histology defines granuloma annulare? Palisaded histiocytes surrounding foci of necrobiotic collagen with abundant dermal mucin — a non-caseating palisading granuloma. ### Which GA subtype is associated with diabetes mellitus? The generalised subtype in adults, which justifies screening for diabetes, dyslipidaemia and thyroid dysfunction. ### What are subcutaneous granuloma annulare nodules called? Pseudorheumatoid nodules — deep nodules on children's limbs with histology of GA but negative rheumatoid factor and no arthritis. ### Does localised granuloma annulare require treatment? No — it is self-limiting in most patients within two years; intralesional or potent topical corticosteroids are optional for cosmetic or persistent lesions.