Are these red spots head lice bites? Actually no, the red spots on the back of your child’s neck are an allergic rash in response to the head lice bites.  After about 2 months of head lice infestation, some children develop an allergic reaction to the lice bites. The allergic reaction manifests itself by producing a rash primarily on the back of the neck. This rash may persist for up to 2 weeks after you have gotten rid of head lice. Benadryl cream can help with the itching symptoms.