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Updated: Aug 4, 2026

Granulocyte-dependent Autoantibody-induced Skin Blistering
Published on: October 12, 2012
Extensive subcutaneous fibrosis in a patient treated with alum precipitated allergenic extract
N A Orfan1, M S Dykewicz, L Barnowsky
1Division of Allergy and Immunology, Bassett Healthcare, Cooperstown, New York, USA.
Background:
Alum-precipitated allergenic extract (Allpyral) used for immunotherapy has been associated with subcutaneous nodule formation at injection sites.
Objective:
We describe a severe localized reaction at the site of Allpyral injections and evaluate possible mechanisms for this reaction.
Methods:
Case report with cutaneous patch testing and CAT scan imaging.
Results:
The patient developed extensive subcutaneous inflammation and fibrosis with overlying skin changes which appear to be permanent. CAT scan findings were corroborative and cutaneous patch testing to aluminium was positive.
Conclusions:
Alum-precipitated allergenic extract used for immunotherapy caused extensive subcutaneous fibrosis with overlying skin changes at the site of injections. The lesions are disfiguring and appear to be permanent. This may be due in part to a type IV hypersensitivity response to the aluminum component of Allpyral extract. A CAT scan was valuable in demonstrating structural changes associated with this lesion.

