Scalp psoriasis

Pharmacy teams can treat mild scalp psoriasis with coal tar-based shampoos. However, where lesions have thickened plaques, a descaling agent with anti-inflammatory, antipruritic and anti-scaling properties should be used before a coal tar product is applied.

Descaling products such as Cocois or Sebco ointment should be massaged generously into the affected areas and left in contact for at least two hours, or preferably overnight. After two hours, or the next morning, a mechanical comb can be used to lift off the softened scale before washing.

Coal tar shampoos should remain on the skin for five to 10 minutes before being washed out. Once scale is controlled, they can be used once or twice weekly for maintenance, and a descaling agent can be restarted if plaques thicken again.

For scalp psoriasis that does not respond to OTC coal tar products, prescription options include potent topical corticosteroids, vitamin D analogues, or a combination of both. Evidence suggests that a potent corticosteroid plus a vitamin D analogue is the most effective approach.