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[Hypersensitivity reactions to insulin].

BACKGROUND
Hypersensitivity reactions to insulin are infrequent, yet of clinical importance. The mechanisms of hypersensitivity involved can be of three types: I, III and IV.


OBJECTIVE
To describe the pathophysiology of hypersensitivity to insulin, its clinical features and diagnostic and therapeutic approach, that help identify the cases of allergy to insulin and begin a treatment, or if necessary, to refer patients to a specialists or appropriate medical attention.


METHODS
An electronic search of papers related to insulin hypersensitivity was performed in PubMed and the articles selected were those considered the most relevant for this review.


RESULTS
Thirty eight papers about pathophysiology, mechanisms of injury and the different types of insulin involved in hypersensitivity reactions were included. Likewise, information for the diagnosis of insulin hypersensitivity and some options of treatment for first contact physicians or the referral of patients to specialists in endocrinology and allergy were included.


CONCLUSIONS
Insulin hypersensitivity has a low prevalence and diverse clinical manifestations. The different types of insulin suitable allow the majority of cases of hypersensitivity to continue the treatment in a efficient and flexible manner.