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Topical antipsoriatic (anthralin) Pregnancy: Avoid — limited human data; alternatives well-established.

Dithranol

Brand names: Dithrocream, Micanol

Adult dose

Dose: Short-contact regimen (preferred): apply 0.1% to plaques OD for 10–30 min initially; titrate strength up to 1–2% over 2–3 weeks; wash off thoroughly. Longer-contact (specialist/inpatient — Ingram regimen): higher strength applied overnight under stockinette dressing in tar-pack regimens.
Route: Topical
Frequency: Once daily
Apply ONLY to plaques — avoid normal skin (causes burning and pigmentation). Wear gloves. Wash hands and equipment immediately after. Stains skin temporary brown-violet (resolves 1–2 weeks); permanently stains clothing, bath, towels.

Clinical pearls

  • Largely a 'specialist' historic option for chronic plaque psoriasis — mostly displaced by topical calcipotriol-betamethasone combinations (Dovobet/Enstilar) and biologics for moderate–severe disease.
  • Short-contact 'minutes therapy' (10–30 min OD) is now the standard: equivalent efficacy to traditional Ingram overnight regimens but better adherence and fewer staining issues.
  • Permanent staining of bath enamels, tiles, fabrics — counsel patients about wearing old clothes, using a designated towel, lining bath if used.
  • Strength titration: start at 0.1% for 10 min/day; increase by 5–10 min every 1–2 days as tolerated; step up strength every 5–7 days only if tolerated.
  • Useful niche: stable plaque psoriasis on resistant body sites (elbows, knees) where topicals have failed; in-patient psoriasis day-care units.
  • Inverse psoriasis (flexures, genitals) — DO NOT apply: marked irritation.

Contraindications

  • Acute or pustular psoriasis
  • Erythrodermic psoriasis
  • Application to face, genitals, intertriginous areas
  • Hypersensitivity

Side effects

  • Skin irritation: erythema, burning, blistering at application site (intensity-related — start low strength)
  • Brownish-violet skin staining (resolves)
  • Permanent staining of clothing, bedding, baths, sinks
  • Folliculitis
  • Conjunctival irritation if accidental eye contact

Interactions

  • Other topical psoriasis treatments (topical steroids, calcipotriol, retinoids): apply at different times — not simultaneously to same area
  • UV phototherapy (Ingram regimen): synergistic in psoriasis day-care units

Monitoring

  • Plaque thickness and erythema response at 4–6 weeks; PASI / BSA assessment

Reference: BNF 90; SmPC Dithrocream; BAD Psoriasis Guideline 2017 (updated 2022); NICE CG153 (Psoriasis). Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways