Persistent Subcutaneous Nodules in Patients Hyposensitized With Aluminum-Containing Allergen Extracts

Persistent nodules at injection sites (aluminium granuloma)—clinicopathological study of 14 cases with a diverse range of histological reaction patterns

“…Again, attention to the presence of the characteristic histiocytes will lead to the correct diagnosis. This pattern of reaction has also been described in previous reports of injection site swellings, the lesions being termed ‘aluminium hydroxide granulomas’ 3,5 , 6,8 . Cominos et al .…”

“…The peculiar appearance of these histiocytes results from the ingestion of aluminium salts, as shown by electron microscopy and energy‐dispersive X‐ray microanalysis. Previous reports of vaccination site reactions have also described similar mixed inflammatory cell infiltrates and fibrosis, together with histiocytes with granular cytoplasm containing aluminium 5,6 , 8 . Similar changes have also been seen in swellings arising after desensitization injections 9 …”

“…An early report described such persistent swellings occurring after influenza vaccination 1 . Subsequently, other cases have also been described, following vaccination 2–7 or desensitization 8,9 . The preparations used in these injections employ an adjuvant aluminium salt to which the relevant antigen is adsorbed with the aim of prolonging and augmenting the immune response to the antigen.…”

Vaccination-induced cutaneous pseudolymphoma

“…1 On another hand, locoregional reactions after a chronic, persisting course over several months or even years have also been described after immunization with aluminium-adsorbed vaccines or hyposensitization solutions. [2][3][4][5][6] In these cases, histopathologic studies of skin lesions revealed either a histiocytic foreign body reaction, mostly in early lesions, 7,8 or a lymphoid infiltration showing a granulomatous reaction with or without necrosis, sometimes with the presence of eosinophilic crystalline material. [2][3][4][5][6]9,10 Cutaneous lymphocytomas, also called cutaneous lymphoid hyperplasia (CLH), are benign cutaneous infiltrates predominantly composed of B cells showing a follicular architecture.…”

Mechanistic actions of the risks and adverse events associated with vaccine administration

“…Early lesions are characterized by histiocytic foreign-body reaction; later lesions show delayed hypersensitivity granulomatous reaction. 44 Concomitant aluminum contact hypersensitivity might occur in a subset of patients, but progression to anaphylaxis has not been described. Immunotherapy evaluations comparing aluminum-adsorbed versus calcium phosphate-adsorbed antigens noted no clinical differences in injection reactivity.…”