Skin reaction and fever after treatment with pegvisomant in a patient with acromegaly

Background: Pegvisomant is a growth hormone receptor antagonist approved for the treatment of acromegaly. Documented adverse effects include headache, injection-site reactions, flulike syndrome, and reversible elevation of hepatic enzymes. Skin manifestations at the injection site are reported in ~ 11% of patients and are characterized as erythematous, self-limited reactions that neither require treatment nor lead to drug discontinuation.Objective: This report describes a skin reaction and fever occurring after treatment with pegvisomant in a patient with acromegaly.Case summary: The patient was a 54-year-old white woman with acromegaly (weight, 85 kg; height, 170 cm). At the time of consultation, her medication regimen was levothyroxine 150 μg/d for hypothyroidism and amlodipine 5 mg/d for hypertension. She started treatment with the somatostatin analogue octreotide acetate 20 mg every 4 weeks, which was then adjusted to 30 mg. Treatment was associated with only partial suppression of insulinlike growth factor-1 concentrations (from 980 ng/mL to 352, 632, and 480 ng/mL at 3, 6, and 9 months, respectively). At this point, octreotide was discontinued and treatment was initiated with pegvisomant 10 mg/d SC. This treatment was initially well tolerated, but after 11 days, she developed an intense erythematous pruriginous reaction at the injection site accompanied by fever (39°C) for 48 hours and, simultaneously, similar lesions at each site of the previous injections. Pegvisomant was discontinued and methylprednisolone 40 mg/d was started, followed by complete disappearance of the lesions in 5 days. Based on the Naranjo algorithm, the adverse reaction observed was probably related to pegvisomant treatment (score = 6).Conclusions: We report a patient with acromegaly who developed a skin reaction and fever probably associated with pegvisomant administration. The reaction subsided 5 days after the drug was discontinued and methylprednisolone treatment was given.