Acne on the chin and hard lumps may be as follows: 1. Local inflammatory reaction or swelling formed by inflammatory acne, which is mostly due to infection secondary to local inflammation of the sebaceous glands of hair follicles, such as infection secondary to Propionibacterium acnes, or inflammation formed by Staphylococcus aureus infection; 2. Inflammation formed by local sebaceous cysts, or cystic acne; 3. Soft tissue formed by local trauma Oedema secondary to infection; 4. Localized redness and swelling due to herpes virus infection is also possible. Because after herpes simplex infects the skin, it may lead to blisters on the basis of local erythema, or even the appearance of redness and swelling of the area, so the symptom of having hard lumps appears.