InflammatoryCTCL DDxICD-10 L28.1
Prurigo nodularis
PN · nodular prurigo · Hyde's disease
Prurigo nodularis is a chronic pruritic disorder characterised by symmetric, intensely itchy hyperkeratotic nodules on extensor surfaces. It results from a self-perpetuating itch-scratch cycle and is associated with atopic eczema, chronic kidney disease, HIV, lymphoma, lithium, opioids and idiopathic chronic pruritus. Differential diagnosis includes hypertrophic lichen planus, scabies (nodular), cutaneous T-cell lymphoma and keratoacanthoma-like reactive eruptions. UK systemic treatment access remains specialist-led: NICE TA955 does not recommend dupilumab for routine NHS use, and nemolizumab has no final positive NICE technology appraisal identified.
CurrentLast reviewed 16 May 2026
Pathogenesis
- Neuro-immune dysregulation: Type-2 inflammation (IL-4, IL-13, IL-31) drives itch; nerve-fibre hyperplasia in lesional skin.
- Itch-scratch cycle perpetuates lichenification and nodule formation.
- Often a downstream presentation of underlying disease:
- Dermatological: atopic eczema, contact dermatitis, lichen sclerosus.
- Systemic: chronic kidney disease, hepatobiliary disease, thyroid disease, anaemia, lymphoma, HIV.
- Neurologic: peripheral neuropathy, post-herpetic neuralgia, brachioradial pruritus.
- Drug: lithium, opioids, EGFR / immune-checkpoint inhibitors.
- Psychogenic: anxiety, depression, OCD.
Clinical features
- Discrete, hyperkeratotic, dome-shaped 0.5-3 cm nodules in symmetric distribution on extensor limbs, upper back, abdomen.
- Spares mid-back (the "butterfly sign" — areas the patient cannot reach).
- Excoriation, scarring, post-inflammatory hyperpigmentation; sometimes lichenification background.
- Intense itch, often worse at night; sleep disturbance.
- Chronic disease — typically >6 weeks duration when diagnosed.
Investigations
- Skin biopsy if diagnosis uncertain: pseudo-epitheliomatous hyperplasia, dermal fibrosis, nerve-fibre hyperplasia; rule out CTCL, lichen planus, keratoacanthoma.
- Bloods: FBC, U&E, LFT, TFT, ferritin, glucose / HbA1c, HIV, HepB/C, IgE.
- Consider CT chest / abdomen / pelvis or PET if B-symptoms or unexplained.
- Patch testing if contact dermatitis suspected.
- Psychological / psychiatric review if mood disorder, anxiety, neurodermatitis component.
Differential diagnosis
- Hypertrophic lichen planus — violaceous polygonal plaques, Wickham striae; shins.
- Nodular scabies — fewer, smaller nodules; genitals / axillae; mites in burrows.
- Mycosis fungoides / CTCL — biopsy + TCR rearrangement.
- Multiple keratoacanthomas / Grzybowski-eruptive KA.
- Reactive perforating collagenosis — central umbilicated keratin plug.
- Cutaneous metastasis, lymphoma, mastocytoma.
- Bullous pemphigoid (pre-bullous urticarial phase).
Management
- General: bland emollients, breathable cotton clothing, cool compresses, nail trimming, behavioural strategies.
- Topical first-line:
- Super-potent corticosteroid (clobetasol propionate 0.05%) under occlusion or impregnated bandages.
- Intralesional triamcinolone (20-40 mg/mL).
- Topical calcineurin inhibitors / capsaicin.
- Phototherapy: narrowband UVB, PUVA for diffuse disease.
- Systemic:
- Gabapentin / pregabalin (off-label, for neuropathic itch).
- Sedating antihistamines (hydroxyzine, doxepin).
- Methotrexate, ciclosporin, azathioprine for refractory disease.
- Naltrexone (low-dose).
- Biologics:
- Dupilumab — licensed for adults with moderate-to-severe PN who are candidates for systemic therapy, but not recommended by NICE for routine NHS use (TA955).
- Nemolizumab — anti-IL-31 receptor antibody with OLYMPIA trial evidence and UK marketing authorisation; no final positive NICE TA identified. NICE evaluation ID6451 / GID-TA11566 is paused for commercial discussions.
- Treat underlying systemic cause (CKD, thyroid, anaemia, malignancy).
References
- Yosipovitch G et al. Prurigo nodularis: a comprehensive review. Am J Clin Dermatol. 2022;23:739-747.
- Ständer S et al. Trial of nemolizumab in moderate-to-severe prurigo nodularis (OLYMPIA-2). N Engl J Med. 2023;389:1579-1589.
- NICE TA955. Dupilumab for treating moderate to severe prurigo nodularis. London: NICE; 2024.
- NICE GID-TA11566 / ID6451. Nemolizumab for treating prurigo nodularis. London: NICE; evaluation paused for commercial discussions; accessed 18 May 2026.
- British Association of Dermatologists. Prurigo nodularis — patient information leaflet. London: BAD; 2024.
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.