No solid tests exist that can diagnose atopic dermatitis. Each person experiences a unique combination of symptoms which vary over time. A doctor diagnoses atopic dermatitis based on how many "major" and "minor" features a patient has. To have atopic dermatitis, a patient must have three or more features from each of the two categories:
Major Features
- Intense itching
- Characteristic rash in typical locations
- Chronic or repeated symptoms
- Personal or family history of atopic dermatitis, hay fever, or asthma
Minor Features
- Early age at onset.
- Xerosis - Dry, rough skin.
- Pityriasis alba - Patches of hypopigmented, or lighter, skin. This occurs more often in infants than in older children.
- Ichthyosis - Severe dryness and scaling of the skin causing it to look like fish scales.
- Hyperlinear palms and soles - Dry, prominent, permanent creases in the palms and soles.
- Keratosis pilaris - Fine, flesh-colored or slightly red plugs on the backs of the arms, the outside of the thighs, buttocks, and face.
- Hand or foot dermatitis - Glistening red, scaling, and cracking skin on the hands or feet.
- Chelitis - Scaliness of the lips and the skin in the corner of the mouth.
- Nipple eczema - Cracking and peeling of the skin of the areolae, most often in young girls at the beginning of puberty.
- Susceptibility to skin infections - Bacterial infections and viral infections like herpes simplex.
- Positive allergy skin tests - A positive test may be an error because the skin is overly sensitive. Skin tests alone are not used to diagnose atopic dermatitis.
- Dennie-Morgan lines - Creases below the lower eyelids.
-
Dark circles around the eyes (allergic shiners) - A blue-gray discoloration of the skin around the eyes, especially under the eyes, associated with nasal congestion.
What About Allergy Tests?
Skin prick allergy tests and blood tests are being studied heavily, but they are still not as useful for diagnosis as the major and minor criteria above. Skin prick allergy tests may be positive only because the skin is overly sensitive, and exposing it to multiple chemicals can cause surrounding skin to become even more sensitive. Blood tests are available that measure an allergic response in the blood. But these tests are not recommended in most cases because they are inaccurate in people with atopic dermatitis.What if You Think You Have Atopic Dermatitis?
The simple answer is you should be seen by your regular healthcare provider who likely can take care of atopic dermatitis. But if you or your doctor you have any questions about your diagnosis, you should see a dermatologist.Sources:
Bolognia, Jean, et al., eds. "Atopic Dermatitis." Dermatology. New York: Mosby, 2003: 200-12.
Hanifin, Jon, et al. "Guidelines of Care for Atopic Dermatitis." Journal of the American Academy of Dermatology 50(2004): 391-404.
Rowlands, Debra, Susan Tofte, and Jon Hanifin. "Does food allergy cause atopic dermatitis? Food challenge testing to dissociate eczematous from immediate reactions." Dermatologic Therapy 19(2006): 97-103.
Simpson, Eric, and Jon Hanifin. "Atopic Dermatitis." The Medical Clinics of North America 90(2006): 149-167.
