Bleomycin has progressively been used to treat low-flow vascular malformations 
in children. No significant systemic side effects have been reported in large 
series after low doses, but some authors are still concerned about its use. We 
report a case of a severe acute lung toxicity after a low dose of a second 
bleomycin intralesional injection in a 5-year-old girl. She had no risk factors 
and presented a cervical low-flow venous malformation. Twenty-four hours after 
this second administration, she presented with fever and respiratory distress. A 
chest radiograph showed bilateral opacities and computerized tomography revealed 
extensive and diffuse lung ground-glass opacities. The patient started to 
receive intravenous methylprednisolone, but she experienced progressively 
increased dyspnea, and montelukast was added. She improved and was discharged 
from the hospital without oxygen support, with montelukast and prednisolone for 
tapering doses during months. Five months after onset, the patient is developing 
well, is active, and walks and talks without dyspnea. A new low-dose computed 
tomography shows improvement in radiologic findings. This is the second case of 
pulmonary toxicity observed in a child after bleomycin intralesional 
administration, and the first reported after the lowest dose of this drug to 
date (7 mg: 0.28 mg/kg; 10 U: 0.4 U/kg). A delay in the diagnosis and treatment 
of this complication can be fatal. Any physician who treats these patients must 
be alert and consider this complication in children with respiratory symptoms 
after bleomycin sclerotherapy. Early detection of pulmonary toxicity would allow 
prompt therapy and could avoid pulmonary damage.