Indications
Dithranol (also called anthralin) is a cream, ointment or paste used on the skin to treat chronic plaque psoriasis, the thick, scaly, red patches that last a long time. It is not used for acute, inflamed or pustular psoriasis.
How It Works
In psoriasis, skin cells grow and shed much too fast. Dithranol slows down this overgrowth and reduces inflammation in the plaques, so they gradually flatten and clear. It works partly by producing short-lived reactive molecules in the skin cells.
Dosage and Administration
Use exactly as directed by your doctor or on the label. Treatment usually starts with the lowest strength and is increased slowly. A common method is short-contact therapy: apply a thin layer only to the plaques, leave it on for a short time (often 10 to 30 minutes, as advised), then wash it off thoroughly with lukewarm water. Protect the surrounding normal skin, for example with petroleum jelly, wear gloves, and wash your hands afterwards. For external use only.
Interactions
Avoid using other irritating skin products on the same areas, unless your doctor advises it. Using it at the same time as strong topical steroids or after stopping them should be supervised by a doctor, because psoriasis may flare.
Contraindications
- Allergy to Dithranol or any ingredient.
- Acute, unstable, inflamed or pustular psoriasis, or erythroderma (red skin all over).
- Do not apply to the face, genitals, skin folds, broken skin or near the eyes.
Side Effects
A burning feeling and redness of the treated skin are common, especially if the strength is increased too fast. Dithranol stains skin, hair, nails, clothes, bedding and bathroom fittings purple-brown; skin staining fades after treatment stops.
Stop using it and get medical help if you have severe burning, blistering or spreading redness, swelling, eye irritation after accidental contact, or signs of a severe allergic reaction.
Pregnancy and Lactation
Little is absorbed through the skin, but safety in pregnancy and breastfeeding is not fully established. Use only if your doctor advises it, and do not apply to the breast area while breastfeeding.
Precautions and Warnings
- Keep away from the eyes; if it gets in the eyes, rinse well with water.
- Wear old clothes and use old towels and bedding, as staining is permanent on fabric.
- Rinse the bath or shower with hot water first, then clean, to reduce staining.
- Do not increase the strength or contact time faster than advised.
Overdose
Leaving it on too long or using too strong a preparation can cause marked burning and redness. Wash it off at once and soothe with a bland moisturiser; contact a doctor if the reaction is severe. If swallowed, contact a doctor.
Therapeutic Class
Topical antipsoriatic agent.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Keep the container tightly closed.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.