Pus on the head of the following reasons: 1, infection, the most common may be infected with staphylococcus aureus, fungi, mites lead to, after the infection will be localized redness, swelling, heat, pain; 2, seborrheic dermatitis, because of the excess oil of the skin, resulting in seborrheic dermatitis; 3, trauma, skin injuries may be skin infections, gradual inflammation formation of pus bags. So if there is a lump, you need to go to the hospital in time, clear reasons, according to different reasons for different means of treatment, if it is a fungal infection, you need to use antifungal drugs, if it is a bacterial infection, you need to use antibiotics, such as caused by trauma, can also lead to lumps, you need to avoid trauma, pay attention to personal hygiene, to prevent the occurrence of abscesses.