Combination of symptoms caused by protein shortage in the diet leading to a deficiency in certain amino acids (elements in protein, necessary for building tissues in the body), and possibly also a shortage of minerals and vitamins. The condition occurs especially in children, and mostly in developing countries with chronic food shortage. Symptoms are slow growth, abnormal pigmentation and ulceration of the skin, stomatitis (inflammation of the mucous membrane of the mouth), enlarged liver, vomiting, diarrhoea, emaciation with breakdown of muscular tissue and oedema. Diagnosis is on the basis of these symptoms, possibly supplemented by tests such as removal of a piece of liver tissue, which will show characteristic changes (fattiness and formation of connective tissue). The condition should be prevented as much as possible by good dietary education and hospital treatment of problem cases. Treatment is by provision of sufficient protein in the food; shortages may need correction by infusion. Treatment is difficult at an advanced stage; in young children particularly there is a danger that brain development may have been excessively impaired by the.protein shortage, and subsequent adequate feeding cannot cure this.