Dithranol

Dithranol has been used in the treatment of psoriasis since the nineteenth century. It is a highly effective treatment if used correctly, with no significant long-term side effects. Dithranol preparations are used to treat well-defined plaques of psoriasis and need to be applied carefully to avoid irritating non-affected skin. It is used as ‘short contact therapy’ away from the face, flexures and genitals.

Dithranol preparations come in ointments or creams. You should always start with the lowest strength and apply the ointment to the plaques for 15 to 30 minutes a day and then wash it off. Increased strengths can be introduced weekly unless an irritation occurs. Dithranol takes longer to work than steroids, in many cases up to 6 weeks.

Tips

· Wear plastic disposable gloves when applying Dithranol and wash hands thoroughly after application.

· Dithranol must only be applied to the psoriatic patches (avoid normal skin as this will be stained a brownish colour and may produce inflammation and soreness) and must be rubbed in well. Any excess should be wiped off.

· Dithranol also stains clothes and sheets. It would be best to use old pyjamas and sheets and rinse them in cold water as ordinary soap and some washing powders can increase staining.

· Baths may be stained. If possible, have a shower after using dithranol treatment, as ceramic shower tiles should rinse clean; if they do not, use a little bleach.

· If staining of the skin occurs in the centre of the plaques of psoriasis, this means the psoriasis is starting to clear.

Dithranol is a time consuming treatment but can be very effective if used properly so you need to be well motivated to carry it out.