Pustular psoriasis is not common. Pustular psoriasis affects all races. Pustular psoriasis can be generalized and can include fever, malaise, and superficial pustulation; or it can be localized and have pustules on the palms and soles. In Japan, only about 7.46 people per 1,000,000 have pustular psoriasis. In adults, it affects men and women equally. In children, it affects boys somewhat more often than girls. The pustules often start their cycle with a yellowish colour as a result of white blood cells (polymorph leucocytes) building up inside them. During the course of the following 7 to 14 days the yellowish colour is lost; the pustule reduces in size and becomes capped by a brown scale of skin.
It can be provoked by some internal medications, irritating topical agents, ultraviolet light overdoses, pregnancy, systemic steroids, especially sudden withdrawal of systemic or topical steroids, infections, perspiration or emotional stress. A strong association with smoking has also been identified, the mechanism of which is uncertain but may be linked to the products of smoking encouraging the inflammatory cells to accumulate in the epidermis (the top layer of the skin). It also happen due to excessive alcohol intake is associated with deterioration and lead to in the production of pustular psoriasis.
Scaly patches containing pus appear on the palms of the hands and the soles of the feet. Sometimes, and more seriously, they cover other parts of the body too. Initially the skin becomes dry, fiery red and tender.
Generalised pustular psoriasis can be life threatening so hospitalisation is usually required. The aim is to prevent further fluid loss, stabilise body temperature and restore electrolyte imbalance. Characteristically, there is a low level of calcium in the blood (hypocalcaemia). Other changes on blood testing include low plasma albumin and zinc, high ESR (erythrocyte sedimentation rate), raised neutrophil count, reduced lymphocyte count and raised lactate levels.
Methotrexate is the most common treatment for generalised pustular psoriasis. Oral steroids are often prescribed for those who do not respond to other forms of treatment, or have become very ill, but their use is very controversial. PUVA (the photsensitizing drug psoralen plus UVA light) may also be used in the treatment of this condition after it has subsided. Cyclosporin is also a medication that is used.
People with generalised pustular psoriasis often require hospitalisation for rehydration and topical and systemic treatments. These treatments typically include antibiotics and other systemic medications such as acitretin, ciclosporin or methotrexate.