A 53-year-old man initially presented with costalgia and was diagnosed with MM, based on the pathological findings. IgE monoclonal protein was detected by Serum protein electrophoresis (SPEP) and, surprisingly, IgE was elevated to 7,950,000 IU/ml. Monitoring the disease response during treatment, we employed quantification of serum M protein at SPEP, because IgE levels were found to be inaccurate and erratic. The patient was treated with CyBorD. He found injection site reactions to be very burdensome, due to extreme skin changes. The diameter of the hyperpigmentation area was 8 cm. To reduce the severity of this reaction, we used an air sandwich technique, and succeeded in ameliorating the skin changes.