By Vincenzo Ruocco, M.D., Sarah Brenner, M.D., and Eleonora Ruocco, M.D., from the Department of Dermatology, 2nd University of Naples, Naples, Italy, Department of Dermatology, Tel-Aviv Sourasky Medical Center, and Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel. Correspondence: Vincenzo Ruocco, MO, Department of Dermatology, 2nd University of Naples, Via Sergio Pansini, 5, 1-80131 Naples, Italy.
In dermatology, there are typical examples of disorders related to dietary factors. The pathogenic, links between nutritional factor(s) and skin disease may be different.
Nutrient deficiency and nutrient excess are the simplest causes of specific diet-related cutaneous changes: scurvy (vitamin C deficiency) and acrodermantis enteropathica (zinc deficiency) are examples of the first type, and caronenoderma (carotene excess) is an example of the second type. Genetic metabolic defects or enzyme deficiencies, although subtle, may pave the way for the onset of diet-related skin disorders, where a toxic effect is exerted by the dietary factor(s): alcohol intake is responsible for porphyria curanea tarda, and the ingestion of choline- and lecithin-containing foods is the cause of eccnine bromhidrosis, with the typical “fishy” odor that features trimethylaminuria. More often, an immune (and complex) mechanism is involved in the pathogenesis of strictly diet-dependent skin disorders, e.g. atopic dermatitis and food-induced urticaria (related to several foods), dermatitis herpetiformis (gluten), and allergic contact dermatitis (nickel). Finally, cutaneous disorders exist where the pathogenic interference of dietary factors has repeatedly been advocated, but without convincing evidence: psoriasis, seborrheic dermatitis, and acne are the commonest examples of this type.