2.3.1.5　Treatment difficulties

A variety of topical therapies，photochemical therapy and traditional immunosuppressants can reduce skin lesions and relieve symptoms；systemic using of IL-23 monoclonal antibody，IL-17A monoclonal antibody and other biological agents that directly block the IL-23/Th17 cell pathway can quickly remove psoriasis lesions.However，skin lesions of psoriasis often recur after stopping treatment，which is the difficulty of psoriasis treatment.

Psoriasis is an inflammatory skin disease that is associated with multiple comorbidities and substantially diminishes patients'quality of life.Joint damage is the most common complication of psoriasis.About 1/3 of psoriasis patients eventually develop into psoriatic arthritis.Patients with severe psoriasis and early onset psoriasis have an increased risk of cardiovascular and other metabolic diseases，such as diabetes，hyperlipidemia，obesity and atherosclerotic plaque.In addition，patients with psoriasis have a higher risk of mental diseases，such as depression，anxiety and suicidality.The risk of inflammatory bowel disease in patients with psoriasis is four times that of the general population.The exact relationships between these comorbidities and psoriasis and the treatments of comorbidities are also the difficulties in the treatment of psoriasis.(https://www.daowen.com)