Antipsoriatic / Keratolytic Pregnancy: Inadequate evidence of safety in pregnant and lactating women, but coal tar preparations have been used for many years without apparent ill-consequence. Recommended to restrict use in pregnancy and lactation to intermittent use, low concentration, relatively small percentage of body surface, and avoid use during the first trimester.

Coal Tar

Brand names: Alphosyl HC, Capasal, Clinitar, T/Gel Shampoo

Coal tar is a traditional topical keratolytic and anti-inflammatory agent used for chronic plaque psoriasis, seborrhoeic dermatitis and some eczema.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Apply a thin layer to the affected areas, two to three times per day

Route: Topical (cutaneous; Exorex lotion/emulsion)

Frequency: Two to three times per day

Adults and children over 12 years of age: ensure lesions are clean, apply a thin layer two to three times per day to affected areas, massage gently and leave to dry. For young children under 12 years of age and the elderly: the emulsion may be diluted by mixing with a few drops of freshly boiled and cooled water in the palm of the hand. Enhances photosensitivity — avoid direct sunlight after application; do not apply to genital/rectal areas; apply with caution to the face. Fire hazard — instruct patients not to smoke or go near naked flames. Source is the Exorex (coal tar) lotion SPC; dosing for other coal tar formulations is not covered here.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Presence of folliculitis and acne vulgaris
Disease characterised by photosensitivity such as lupus erythematosus or allergy to sunlight
Inflamed or broken skin (open exuding wounds or infection of the skin)

Side effects

Skin irritation
Photosensitivity of the skin
Acne-like eruptions of the skin
Increased risk of skin cancer reported in psoriatic patients treated with combination of coal tar and UVB radiation (epidemiological studies of coal tar alone inconclusive)

Interactions

None known

Clinical monograph

How it works

It has antiproliferative, anti-inflammatory and antipruritic actions on the skin that reduce epidermal cell turnover and scaling, although the precise mechanism is not fully defined.

Prescribing in practice

Coal tar can cause photosensitivity, so advise sun protection and use caution when combined with phototherapy.
It stains skin, hair, clothing and bathroom surfaces and has a characteristic odour, which affects acceptability and adherence.
Avoid application to acutely inflamed, broken or pustular skin and to the face and flexures unless using a preparation formulated for those sites.

Monitoring

Monitor clinically for treatment response, local irritation or folliculitis, and skin reactions when used alongside ultraviolet therapy.

Counselling the patient

Be aware the product stains and has a strong smell; protect clothing and bedding.
Avoid strong sunlight or sunbeds and use sun protection while treated.
Report excessive irritation, burning or spots around hair follicles.

Evidence & guidelines

Coal tar preparations are long-established options for chronic plaque psoriasis and scalp conditions in NICE psoriasis guidance.

Reference: NICE NG220 Psoriasis; BAD Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways