There is an association between contact allergy to aluminium and persistent subcutaneous nodules in children undergoing hyposensitization therapy.

BACKGROUND

The development of persistent itchy nodules at the injection site following hyposensitization therapy with aluminium-precipitated antigen extract has been described in several reports. Occasionally, contact allergy to aluminium has been reported in individuals with such nodules.

OBJECTIVES

To investigate if hyposensitization therapy can induce contact allergy to aluminium and examine if there is any association between persistent subcutaneous nodules and aluminium allergy.

PATIENTS/

METHODS

Sixty-one children with allergic asthma and/or allergic rhinitis participated in the study of whom 37 had had hyposensitization therapy. The study consisted of a non-clinical part based on a questionnaire and a clinical part with a physical examination, self-assessment of itching, and patch testing. To secure an unbiased evaluation of possible reactions, the investigators were blinded.

RESULTS

Contact allergy to aluminium was found in eight participants, all in the exposed group (8/37 versus 0/24, P = 0.02). Examination showed nodules on the upper arms in 13 participants, all in the group exposed to hyposensitization therapy. Nodules were over-represented in patients with contact allergy to aluminium.

CONCLUSIONS

There was a statistically significant association between contact allergy to aluminium and persistent subcutaneous nodules in children who had had hyposensitization therapy.