Avoidance Diets an Option With Systemic Contact Dermatitis

PHILADELPHIA — Children with systemic allergic contact dermatitis can benefit from diets that minimize ingestion of certain foods that contain key allergens, including nickel and cobalt, according to Dr. Catalina Matiz.

"We should be considering [an avoidance diet] in children with a proven contact dermatitis who fail to improve with contact avoidance," said Dr. Matiz, a pediatric dermatology postdoctoral fellow at Rady Children's Hospital in San Diego.

Systemic contact dermatitis (also known as systemically reactivated allergic contact dermatitis) occurs when an exquisitely sensitized person has a skin reaction after systemic exposure—oral ingestion, inhalation, intravenous/intramuscular/subcutaneous exposure. Nickel, cobalt, balsam of Peru (derived from the Myroxylon pereirae tree and used in perfume and as a flavoring), and formaldehyde derivatives are among the most common triggers of systemic contact dermatitis (SCD).

SCD can present in many ways, including disseminated erythematous papules, vesicular hand dermatitis (pompholyx), and areas of well-defined redness on the buttocks and/or upper inner thighs (baboon syndrome), Dr. Matiz said at the annual meeting of the Society for Pediatric Dermatology.

SCD can present at any age. Exposure to the allergen can cause a flare of the dermatitis in the same area where the initial episode of elicitation occurred, including patch test sites. Some patients may experience systemic symptoms such as nausea, vomiting, diarrhea, fever, malaise, and headaches.

To date, Dr. Matiz—working in the contact dermatology clinic at Rady with Dr. Sharon Jacob—has seen several children with SCD who improved with avoidance diets. Dr. Matiz discussed key foods to avoid for patients with SCD to nickel, cobalt, balsam of Peru, and formaldehyde.

Nickel

The most common presentation of nickel SCD is vesicular hand eczema. The average daily consumption of nickel is 0.22–0.35 mg/day. One study found that 1% of patients with nickel SCD would react to the nickel content of a normal diet—less than 0.5 mg/day (Contact Dermatitis 2006;54:79–86), Dr. Matiz noted.

Interestingly, there is some evidence to suggest that immunologic tolerance can result through small amounts leached into saliva from braces (Contact Dermatitis 2007;56:247–54). In fact, getting braces prior to ear piercings seems to be protective, she said.

Nickel can occur naturally in food or can be added inadvertently by processing, cooking, or storage. Foods that contain relatively high amounts of nickel include dark chocolate, seafood (especially shellfish), legumes, grains, and nuts.

One low-nickel diet has been proposed (J. Am. Acad. Dermatol. 1993;29:1002–7), but a low-nickel diet "is not very child-friendly," Dr. Matiz said. She and her colleagues recommend avoiding chocolate, seafood (especially shellfish), some legumes, grains, nuts, canned foods, leafy green vegetables, and multivitamin supplements/drinks with nickel.

Cobalt

"Cobalt is commonly associated with nickel dermatitis and also presents with vesicular hand eczema," said Dr. Matiz. Importantly, cobalt is a main component of vitamin B12. The average cobalt ingestion is 12 mcg/day.

Last year a point-based low-cobalt diet was published, in which food items were assigned points based on the amounts of cobalt (Contact Dermatitis 2008:59;361–5). Patients were limited to a total of 12 points per day. Flaxseed, chick peas, and lamb liver each count as 7 points. Buckwheat, chili with meat and beans, chocolate, and soy milk each count as 5 points. "Patients found that this was very easy for them to follow," said Dr. Matiz. In particular, patients should avoid Brazil nuts, cow liver, and homeopathic/herbal remedies.

Balsam of Peru

Systemic contact dermatitis caused by balsam of Peru presents as hand and face dermatitis. This natural extract from Myroxylon pereirae is composed of more than 400 different constituents, and therefore its components can show up in lots of products. Patients with SCD to balsam of Peru need to avoid products containing fragrance, for example.

In an adult population, 47% of the patients with balsam of Peru or fragrance mix allergy improved with diet (J. Am. Acad. Dermatol. 2001;45:377–81). Interestingly, the most provocative food allergens are tomatoes, citrus fruit peels, spices, sodas, chocolate, and chili. The specific allergens in tomatoes are cinnamic alcohol and coniferyl alcohol, both of which are found in balsam of Peru, said Dr. Matiz.

Patients on a diet to minimize balsam of Peru ingestion should avoid tomatoes and tomato-containing products, products containing citrus, flavoring agents, spices, wine, beer, gin, perfumed teas, tobacco, chocolate, cough medicines, ice cream, and soda.

Formaldehyde

Patients with SCD to formaldehyde often present with periorbital dermatitis. Formaldehyde is a ubiquitous contact allergen found in many products, including the sweetener aspartame. Aspartame is metabolized to methanol, which then results in the formation of formaldehyde and formate adducts.