Delayed hypersensitivity skin testing in nutritional assessment.

Skin testing is useful in nutritional assessment because decreased immunity is associated with malnutrition. Absence of positive reactions indicates anergy, reaction to one test shows some decreased immunity, and response to two or more tests is considered normal. Variation in number and type of test antigens could lead to contradictory results. Also, conventional intradermal injections vary in antigen strengths, injection techniques, and subjective evaluations, and are also uncomfortable. This study compared results from three, four, or seven antigens in relation to other nutritional indices. Fifty hospitalized men with cancer were assessed with a 23 item Protein Energy Malnutrition Scale and classified as well nourished (60%) or malnourished (40%). Number of tests did not differ in identifying the malnourished; however, the smaller battery misclassified the normal as malnourished twice as often as the seven tests. Misclassification of normal as abnormal could lead to unnecessary interventions, such as total parenteral nutrition, that increase complications and cost of care dramatically.