Presentation

Chronic plaque psoriasis is characterised by well-defined, erythematous plaques with silvery-white hyperkeratotic scale. These typically occur on extensor surfaces, such as the elbows, knees and lower back.

Up to 80 per cent of patients also have scalp psoriasis. Psoriasis can affect the nails too, causing characteristic pitting, subungual hyperkeratosis – a build-up of keratinous material beneath the nail – and onycholysis, where the nail separates from the nail bed.

Several lifestyle factors are associated with worsening disease severity. These include:

• Cigarette smoking
• Higher body mass index
• Alcohol consumption
• Physical inactivity.

A potentially serious comorbidity is psoriatic arthritis (PsA), a chronic inflammatory joint condition that may affect up to one-third of people with cutaneous symptoms. Pharmacy teams should ask about joint pain, stiffness, dactylitis (severe swelling that affects the fingers or toes) and heel pain, and refer where PsA is suspected.