Small bumps next to the back carbuncle may be caused by folliculitis, allergy and other reasons. It is recommended that patients be treated with medication after the specific cause is clarified under the guidance of a doctor. 1. Folliculitis: Because the sebaceous glands in the back are more developed and secrete more oil, there may be folliculitis; you can use mupirocin ointment, fusidic acid ointment and other antibiotic ointment under the guidance of the doctor to carry out the treatment. 2. Allergy: Small bumps next to the canker sores may also be caused by allergies to the medication used to treat the canker sores. After clarifying the cause of the disease, you can take oral antihistamines such as cetirizine under the guidance of your doctor for anti-allergy treatment. For patients with pimples next to canker sores, it is recommended to go to a regular hospital for timely examination to clarify the cause of the disease and treatment under the guidance of a professional doctor.