The skin condition psoriasis, an overproduction of skin cells that causes flaky patches on the surface to form as scales, is mainly thought of as an issue on the body.

In the UK, the NHS estimates that one in 50 people suffer, with varying degrees of severity ranging from minor irritation with long, symptomless stretches to serious cases where it has an incredibly damaging effect on people’s lives.

Psoriasis can appear anywhere on the body or face, but when you consider that the scalp is also skin, it shouldn’t be a surprise that psoriasis often affects this area too, with symptoms such as scaly skin, flaking, itching, inflammation and in extreme cases, hair loss. So special consideration is needed when choosing and using something as basic as shampoo.

Although the cause isn’t completely understood, psoriasis is likely related to a problem with the immune system, making it attack healthy skin cells by mistake. “It is an autoimmune condition with a tendency towards genetic inheritance so there are often other family members who suffer too,” explains Sally-Ann Tarver, Consultant Trichologist at The Cotswold Trichology Centre. “It’s possible to have psoriasis on only the scalp in fairly circumscribed areas, although the entire scalp can be affected. It normally presents as plaques on an inflamed, thickened scalp covered in white scale which sheds profusely. Sometimes the scales become thick and hardened, causing hair to stick down within the hard crust or the crust to grow over or down clumps of hair. This makes treatment particularly difficult as the hair as well as potential loss must also be considered."