Spots and breakouts are caused when sebum, produced by the skin, mixes with dead skin cells on the skin's surface.
Ingrown hairs happen when a hair that’s been shaved or cut grows back into its follicle, instead of out, and gets trapped underneath the skin. This is what causes irritation and inflammation. When this happens, the follicle can become red, bumpy and itchy. People with curly hair are particularly susceptible to ingrown hairs.
Folliculitis is when follicles containing your beard hair become inflamed, and feel tender or painful to the touch. They can become blistered and, if it’s a bacterial infection, may become filled with pus. Folliculitis is usually the result of a bacterial, viral, or fungal infection, although it can also be caused by ingrown hairs.