Clinical

Ulcerations with pegylated interferon injections infrequent but important to note

Last Updated: 2005-07-22 12:05:07 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Pegylated interferon alfa-2b can, in rare cases, cause cutaneous necrosis to develop at injection sites, according to a series of case reports published in the July issue of the Journal of the American Academy of Dermatology.

While this complication is infrequent, patients and doctors should be made aware that it may occur because halting injections to the affected site is required for successful treatment of the necrosis, Dr. Joan Dalmau of the Hospital de la Santa Creu I Sant Pau in Barcelona write.

Dr. Dalmau and colleagues describe the cases of five patients who developed such ulcers. Three patients had chronic hepatitis C, while the other two had chronic myelocytic leukemia.

Four patients were able to continue using the drug, while one, a patient with chronic myelocytic leukemia, had to halt the medication because the ulcer failed to heal. Dosage reduction was required in two patients, while rotating of injection sites was sufficient for the two others.

The cause of such ulcers remains unclear, the researchers note. While excessive coagulation has been suggested, they add, skin biopsy identified thrombosis in only one of the patients in the current series.

"A local immune-mediated inflammatory process in the skin, with eosinophilic infiltration and occasional vasculitis may be involved; inflammatory mediators induced by the prolonged presence of interferon might be important in pegylated interferon alfa-2b related cases," they write.

Because pegylated interferon alfa-2b is now almost exclusively used instead of the non-pegylated form, patients and doctors should be aware of the risk of necrosis so injections at the affected site can be halted, the researchers write. They point out that itching and other skin reactions at injection sites are also more common with the pegylated form of the drug.

"Prevention of pegylated interferon alfa-2b-induced skin necrosis requires competent training in self-injection, with as much variation as possible of the injection site, and particular vigilance in cases of erythema at the injection site, which persists for several days," they conclude.

J Am Acad Dermatol 2005;53:62-66.