[Wells' cellulitis and bacterial necrotizing cellulitis induced by anakinra].

BACKGROUND

Anakinra is a recombinant form of the naturally occurring human interleukin-1 receptor antagonist. It is used in the treatment of rheumatoid arthritis. The most frequent side effects are injection site reactions, which seem to have a toxic mechanism.

PATIENTS AND METHODS

We report two unusual cases of injection site reactions with anakinra: a woman presented Wells' cellulitis of the thigh and a man developed serious bacterial cellulitis distinguished by deep necrosis at the site of the latest anakinra subcutaneous injection.

DISCUSSION

The cases are examples of serious side effects that can occur during treatment with anakinra and underline the need for careful use of this new biological agent.