At 40, Yvonne Smith feels as though she has to “justify” having arthritis, as many people tell her she is “too young” for the condition.

But she has had it since her mid-20s and now her parents, in their 60s and unaffected by arthritis, do her heavy shopping for her.

Ms Smith was diagnosed with psoriasis in her early-20s and with psoriatic arthritis a few years later.

Like psoriasis, it is a long-term condition that can get worse with time. If it is diagnosed and treated, however, the progression can be slowed down.

'Arthritis doesn't just affect old people', says Scot, 40, with the condition since her 20s