Aluminum is a tin-white, malleable, and ductile metal used as a pure metal or in alloys. Contact sensitivity to noninjected aluminum is rare but most commonly occurs during the continual application of aluminum-containing antiperspirants. Aluminum allergy has been reported to be associated with an axillary rash and with hand dermatitis.
The more typical route of sensitization, however, is via the absorption of aluminum through hyposensitization injections and vaccines. Hyposensitization injections are used as treatment for IgE-mediated allergies, and the most commonly used extracts in these solutions are aluminum-contacting antigens. Additionally, aluminum compounds have been widely used as adjuvants in prophylactic and therapeutic vaccines to potentiate the immune response. Aluminum-containing vaccines are prepared by the adsorption of antigens onto aluminum hydroxide or aluminum phosphate gels or by the precipitation of antigens in a solution of potassium aluminum sulfate.
FDA regulations limit the aluminum content of an individual dose of a vaccine to 0.85 mg of elemental aluminum. The diminutive level of aluminum needed in vaccines to induce serious toxicities is evidenced by the undetectable changes in the normal plasma concentration of aluminum (5 µg/L) after intramuscular administration of an aluminum-containing vaccine.
Although the development of painful and pruritic nodules at the site of aluminum-containing injections is a rare event, it is nevertheless the most frequent clinical manifestation of a hypersensitivity reaction to aluminum hydroxide in vaccines and in aluminum-containing antigen solutions. Such nodules have also been associated with hyper- and hypopigmentation, hypertrichosis, and lichenification.
Of individuals who undergo immunotherapy with aluminum-containing allergen extracts, 33 to 70% develop a local immediate or transient inflammatory reaction[10,11] whereas 0.5 to 6% develop nodules weeks, months, or even years after the introduction of aluminum. Garcia-Patos and colleagues described 10 patients who had a persistent nodular reaction at the injection site of allergen extract preparations containing aluminum. The results of patch tests with 2% aluminum chloride in water were positive in five patients. Biopsy specimens from nodules appearing 1 to 9 months after the patients were injected were associated with the histopathologic features of a histiocytic foreign-body reaction. Nodular lesions of greater than 1 year's duration, however, showed a granulomatous reaction.
Some patients with hypersensitivity reactions to aluminum develop dermatitis, either localized or generalized. Cox and colleagues reported on an 18-month-old female child with dermatitis, characterized by acute weeping vesiculation at the vaccination site, that developed 6 months after she received diphtheria and tetanus toxoids and pertussis (DTP) triple vaccine. A patch-test result for aluminum was positive despite no known exposures to aluminum-containing products.
Dermatitis. 2005;16(3):115-120. © 2005 American Contact Dermatitis Society
Cite this: Hypersensitivity Reactions to Vaccine Components - Medscape - Sep 01, 2005.