A rash is not a symptom of a gluten sensitivity, which is marked primarily by digestive symptoms. If you experience a rash after consuming gluten, it is more likely dermatitis herpetiformis -- a rash caused by an autoimmune reaction to gluten known as celiac disease. Celiac disease is more severe than gluten sensitivity, but both require avoiding gluten. Consult a doctor for a proper diagnosis, as left untreated celiac disease can result in long-term damage to your body.
Gluten sensitivity is a reaction to ingesting gluten, a protein primarily found in wheat, barley and rye. The problematic symptoms of gluten sensitivity are the result of the innate immune response -- which is the body's basic, generic defense to what it sees as harmful. Unlike celiac disease, it does not cause long-term damage to the intestinal tract and doesn't produce a long-term autoimmune reaction -- an adaptive immune response that creates a specific reaction. Common symptoms can include bloating, cramping, abdominal pain and constipation or diarrhea. Other symptoms that affect behavior can include depression and the feeling of having a "foggy" head. More severe symptoms can include joint pain and leg numbness. Osteoporosis and anemia can also develop over time.
Celiac disease is essentially a more severe form of gluten sensitivity and has similar symptoms. Unlike gluten sensitivity, however, celiac disease can damage the small protuberances in the small intestine -- the villi -- that are responsible for digesting nutrients. This can lead to long-term digestion-related problems such as chronic fatigue, weakness and malnutrition, as well as damage to the reproductive and nervous systems. The autoimmune response that takes place in the intestines as a result of celiac disease can also spread through to the rest of the body. One possible symptom that can result is a skin rash known as dermatitis herpetiformis.
The immune reaction that takes place with celiac disease releases a type of antibody called immunoglobulin A, or IgA. Once released, the antibody spreads through the blood stream and collects in small vessels just below the skin, which can trigger the rash. Dermatitis herpetiformis is characterized by groups of small blisters on the scalp, elbows, knees, back or buttocks, and the urge to scratch them is usually intense. The National Institutes of Health notes that dermatitis herpetiformis affects between 15 to 25 percent of people with celiac disease. However, those that exhibit dermatitis herpetiformis typically have none of the digestive symptoms typically associated with celiac disease.
Dermatitis herpetiformis usually responds well to antibiotics, according to the National Institutes of Health, but there is no cure for celiac disease or gluten sensitivity. Avoiding gluten is the only way to prevent symptoms from occurring. It is important, however, to get a proper diagnosis from a qualified health practitioner, as many other issues can cause similar rash-like lesions on the skin. Eczema, for example, is a skin irritation that is very similar to dermatitis herpetiformis but has a different cause. Other problems, such as an allergy to wheat, can cause similar symptoms.