Many metals not in the standard series are associated with allergic patch-test reactions in contact dermatitis

This study summarized the experience with more than 1,000 patients in 10 years at Mayo Clinic.

The standard allergen series used in patch testing contains metals that most commonly cause allergic contact dermatitis. However, testing with additional metal allergens is warranted for select patients.

The researchers retrospectively analyzed outcomes of 1,000 patients suspected of having metal allergies.

Patch testing was performed with 42 metal preparations:

- 6 in the standard series
- 36 in the metal series

Patch testing most commonly was performed for patients with:

- oral disease (almost half the patients)
- hand dermatitis
- generalized dermatitis
- dermatitis affecting the lips, legs, arms, trunk, or face

At least one positive reaction was reported in 57% of patients.

Metals with the highest allergic patch-test reaction rates were nickel, gold, manganese, palladium, cobalt, ticonium, mercury, beryllium, chromium, and silver.

Metals with extremely low rates of allergic patch-test reactions included zinc, ferric chloride, and tin.

Metals causing no allergic patch-test reactions were titanium, vitallium, and aluminum powder.

Reaction rates varied depending on metal salt, concentration, and timing of readings.

The study authors concluded that many metals not in the standard series were associated with allergic patch-test reactions.

References:

Patch Testing With a Large Series of Metal Allergens. Medscape, 2012.