Generalized Laser-Induced Erythema Under General Anesthesia in Infants: A Case Series.

OBJECTIVES: Selective photothermolysis with Q-switched ruby laser (QsRL) is used for treatments of dermal melanocytosis. Acute widespread cutaneous manifestations associated with transient systemic effects have rarely been reported. MATERIALS AND METHODS: Patients who developed generalized erythema during QsRL treatment under general anesthesia were retrospectively identified and evaluated. RESULTS: During QsRL treatment, two infants with nevus of Ota and one infant with ectopic Mongolian spots developed generalized erythema. The erythema developed after the initiation of laser treatment rather than after induction of anesthesia. It occurred in non-laser-irradiated areas, including distant regions completely shielded from the laser. The erythema progressed rapidly, resembling an allergic reaction. However, the erythema subsided promptly after QsRL treatment. The borders were distinct without wheals, and reproducibility was observed. In some sessions, transient hypotension followed the erythema. Serum tryptase levels, measured in two infants, were below the cutoff values for anaphylaxis. CONCLUSION: Generalized erythema during QsRL treatment under general anesthesia appears to be transient but may be underrecognized. Laser therapy can induce inflammatory responses, and inflammation-mediated mechanism may contribute to the development of erythema; however, the underlying factors remain unclear.