Aluminum
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[3] and with hand dermatitis.[4]
The more typical route of sensitization, however, is via the absorption of aluminum through hyposensitization injections and vaccines.[5] 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.[6]
FDA regulations limit the aluminum content of an individual dose of a vaccine to 0.85 mg of elemental aluminum.[7] 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.[8]
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.[9] Such nodules have also been associated with hyper- and hypopigmentation, hypertrichosis, and lichenification.[9]
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.[12] 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.[9] 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.[13] 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.[13] 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.
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