Psoriasis: guttate psoriasis

Guttate psoriasis is characterised by multiple small 'tear drop' lesions that tend to affect most of the body. The rash comes on very quickly and may follow a streptococcal infection of the throat. It tends to affect children and young adults and has a good chance of spontaneously clearing.

This chapter is set out as follows:

• Guttate psoriasis is typically triggered 7-10 days after a streptococcal URTI
• It is a common pattern in children and young adults
• While some will go on to develop ordinary psoriasis at a later stage, one third do not have a family history and don’t go on to develop psoriasis in adulthood

Distribution

• An even distribution over the body, especially on the trunk and proximal limbs
• Relative sparing of the face

Morphology

• Small, round-oval scaly papules (palpable) up to one cm in diameter
• In the early stages there may be little scale
• The Köebner phenomenon may be present
• These features should be differentiated from chronic small plaque psoriasis, which has a more insidious (usually) presentation consisting of multiple small flat scaly patches / plaques 

• In mild cases of guttate psoriasis the use of an emollient regimen may be sufficient until spontaneous clearance occurs, usually after two to three months. While natural sunlight in moderation can improve guttate psoriasis, the use of sun-beds is discouraged

• Topical treatment - coal tar preparations eg Exorex ® lotion or Alphosyl-HC ® cream can be beneficial as they can be applied more generally to a large area of skin. Vitamin D analogues can be used but because these treatments are best applied directly to the lesions, with large numbers of lesions application is very time consuming and may not be acceptable to some patients

• Referral to dermatology for a course of narrow-band UVB phototherapy (TL-01) is an effective treatment for widespread / unresponsive cases