Background and design: Based on potential contributions of mast cells to neurofibroma-associated itching, pain, and tenderness, the mast cell blocker ketotifen fumarate (Zaditen, Sandoz Pharmaceuticals Corp, Hanover, NJ) has been proposed as a treatment for these symptoms. To test the hypothesis that ketotifen decreases neurofibroma-associated itching, pain, and tenderness, data were accumulated from two protocols. The first was an open-label protocol involving 25 patients with relatively severe symptoms (1170 patient-months), and the second was a double-blind protocol involving 27 patients with either relatively mild or severe neurofibroma-associated symptoms (316 patient-months). All subjects received either oral placebo or 2 to 4 mg of ketotifen fumarate per day. Using a scale of 1 to 10, symptoms were measured before, during, and after treatment.
Results: Itching severity scores (means) were as follows: for all patients receiving ketotifen, 7.8 before, 2.8 during, and 7.2 after treatment; for ketotifen-treated patients in the double-blind protocol, 6.6 before, 3.9 during, and 6.4 after treatment; and for placebo-treated patients, 6.0 before and 6.0 during treatment. Pain and tenderness severity scores (means) were as follows: for all patients treated with ketotifen, 7.6 before, 3.6 during, and 6.6 after treatment; for double-blind ketotifen-treated patients, 6.3 before, 4.6 during, and 6.1 after treatment; and for placebo-treated patients, 7.9 before and 6.7 during treatment.
Conclusions: Pretreatment, treatment, and posttreatment levels of itching, pain, and tenderness associated with neurofibromas, using both open-label and double-blind protocols, indicate that ketotifen offers a realistic approach to treating these symptoms.