Prophylaxis for Pneumocystis carinii pneumonia ( PCP ) is recommended for all HIV-infected children considered to be at high risk. Approximately 15 percent of children are intolerant to trimethoprim / sulfamethoxazole, the first choice drug for PCP prophylaxis. Since many children are also unable to take or tolerate aerosolized pentamidine, dapsone is a second choice for PCP prophylaxis. The most favorable dose regimen for dapsone has not been established.