Psoriasis is a chronic inflammatory skin condition characterised by clearly defined, red and scaly plaques (thickened skin). Psoriasis has a strong genetic component and is due to abnormal processes involved in the regulation of the immune system. Individuals may have flares of psoriasis in response to stress, injury, medications and infections (particularly streptococcal tonsillitis).

Psoriasis is not contagious, therefore, affected children do not need to be isolated from other children.

Although there is no cure for psoriasis, there are many options for improving the symptoms. Topical treatments applied directly to the affected patches of skin include steroid and vitamin D creams. Coal tar is a treatment that has been used for decades and works well, but is a bit smelly and messy so some people are reluctant to use it.