It is a chronic leather disease, and it is one of the autoimmune diseases that causes peeling rash in skin and can affect nails and scalp and may affect the joints in a small percentage of people.
The disease causes inflammation in the skin areas, so the inflamed area becomes reddish and covered with white or silver scales and usually appears on the joints, such as (elbows and knees) and it can appear in any area of the body, including (hands, feet, neck, scalp, and face) Psoriatic arthritis is called this name due to the inflammation of joints associated with it.
Symptoms differ from person to person.
It is not clearly known the cause of psoriatic, but environmental and genetic factors play a role in the disease.
The doctor relies on reaching the diagnosis of the disease by prescribing the patient to the symptoms he complains about and a clinical examination, and the patient may need to perform some blood & radiation analyses to help the doctor reach a proper diagnosis and to distinguish the disease from similar types.