In this summer edition of Ask the Ecz-perts, we talk campfires, poison ivy/oak, bug bites and heat rashes.
Published On: Nov 9, 2020
Last Updated On: Oct 30, 2020
In Ask the Ecz-perts, leading medical experts answer your most pressing questions about eczema and its related conditions.
In this edition of Ask the Ecz-perts, Ari Zelig, MD, allergist and immunologist at the Asthma and Allergy Associates of Florida, answers questions about allergy shots, patch testing, contact and environmental allergens, and allergic reactions.
Patients with atopic diseases have skewed TH2 immune responses. The arms of the immune system, which are overactivated in atopy, cause inflammation and production of a specific immunoglobin E (IgE) targeted against environmental and food allergens.
Eczema is often the first step of the atopic march. Food allergy, rhinitis and asthma are the other commonly associated atopic conditions. Some patients are lucky enough to outgrow eczema but then develop these other atopic conditions.
Eczema is a complex skin disease with both genetic and environmental components. Any family history with atopy — diseases such as food allergy, eczema, allergic rhinitis (hay fever) and asthma — is a risk factor for development of eczema and other atopic conditions among children.
A small percentage of people develop eczema later in life. It may occur alone, but sometimes people do develop asthma or environmental allergies after childhood as well. You can consider immunotherapy (allergy shots) if you have environmental allergies. Allergy shots may protect against the development of allergic asthma.
Allergy shots are typically given to patients with asthma and allergic rhinitis/hay fever. They may benefit some patients with eczema as well. The best data that we have for allergen immunotherapy (allergy shots) is with a dust mite allergy. Allergy shots may decrease the inflammatory responses you have on the skin due to environmental allergy exposure.
The location affected by eczema often changes. It usually starts on the torso and face, and later affects typical sites like elbows and knees. Why it affects those areas, honestly, I am not sure. Some people have eczema that is way worse on the hands and feet — we call this variant dyshidrotic eczema.
If an atypical location is involved, patch testing may be considered in order to evaluate for a possible contact dermatitis diagnosis. I wouldn’t patch test often unless suspicion is high for a new contact allergen playing a role. If it seems a particular product is becoming problematic, you can consider repeating the patch test.
Ongoing runny nose and congestion are symptoms that are usually due to inhaled allergens. If there is a dog in the home, you can certainly have your child tested for a possible dog allergy as well as other environmental allergens. At age 1, it is unlikely to be pollen related.
You can be allergic or sensitive to ingredients in toothpaste. I would avoid sodium lauryl sulfate. Try CloSys toothpaste. I would advise patch testing so you can get to the bottom of which allergen may be causing this.
Contact dermatitis with metals can lead to implant failure. If you have a history of metal hypersensitivity, patch testing to an array of metals commonly used in orthopedic implants is important before surgery. Depending on patch test results, your allergist can help guide your orthopedic surgeon in their choice of implant. If you do not have a history of metal hypersensitivity, however, you don’t need to have patch testing done in advance.
You are referring to a systemic contact dermatitis, which is a type 4 hypersensitivity reaction. It is immune mediated and specifically involves T cells. Systemic contact dermatitis presents with a rash, which occurs due to ingestion of a typical contact allergen. Sometimes this can occur with medications that contain allergens. Reactions to nickel-rich foods is possible but very rare.
Contact dermatitis is a type 4 hypersensitivity reaction and often coexists with eczema. Patch testing is helpful to determine which contact allergen is playing a role. The location of your eczema may be a clue that a contact dermatitis is involved. For example, eyelid dermatitis can be a sign of allergy to a contact allergen in cosmetics or shampoo. Hand dermatitis can be due to an allergen in hand soap. Rashes around jewelry may be a sign of a nickel allergy. I advise seeing a dermatologist or allergist for patch testing.
Ari Zelig, MD, allergist and immunologist, Asthma and Allergy Associates of Florida.