According to researchers, several different factors can potentially trigger atopic dermatitis, including allergies and emotional stresses. Researchers have discovered that atopic dermatitis is related to the development of other allergies, such as allergic rhinitis and asthma, in most children.
In one study of adults who had atopic dermatitis as children, about 35% had no skin problems but had asthma or hay fever. In addition, only 20% still had atopic dermatitis and about 15% had both atopic dermatitis and asthma or hay fever.
In some cases, inhaled allergens (like dust mites or animal dander) may cause flare-ups. A bacterial, fungal or viral infection can also result in a flare-up. Food allergies may trigger an episode in children, but rarely in adults.
Atopic dermatitis is a chronic disease, and symptoms can disappear and recur over time.
The skin of an infected individual is flaky, red and itchy. The skin covering the joints and face is most commonly affected. The skin also becomes susceptible to bacterial infections. Scratching the affected areas of the skin can increase the risk of bacterial infection.
Most cases of atopic dermatitis can be diagnosed from a medical history and a physical examination.
Skin testing may help confirm that a food allergy is triggering dermatitis flare-ups. During a skin test, an extract of the suspected allergen is used to prick the skin. If the area on the skin that was pricked becomes red and swollen, the patient is allergic to the substance. However, some individuals have a positive reaction to a food that is not causing the eczema.
Also, skin tests can be difficult if the patient has an existing rash. In such cases, a blood test, like the RAST (radioallergosorbent test) is used to detect food-specific antibodies in the blood. Another lab test then analyzes a blood sample for the presence of eosinophils, cells, which cause inflammation.
A food challenge can also determine whether a specific food is triggering dermatitis. The suspected food is removed from the diet and then gradually added back into the diet. The healthcare provider monitors to see if the patient's symptoms recur.