Severe acne usually involves pus filled lesions and angry red bumps. There is also sometimes involvement of the chest and back.
Acne prone skin occurs when the oil glands over-react to normal stimulli. I advise a few cardinal rules to follow.
Your diet can influence how much your acne flares up. Caffeine (in coffee and tea) stimulates your oil glands. The more caffeine you take, the worse your flare-ups will be.
Exposure to extreme hot or cold environments means that blood flow to the skin increases. This will also cause your acne to flare up.
Taking excessively hot or spicy food or drinking alcohol, again, increases blood flow to the skin and can lead to flare ups.
Smoking impairs your healing and prolongs your recovery time post-acne flare-up.
I would consider starting on oral isotretinoin. This will effectively re-programme your oil glands permanently. You can expect to be on this treatment for between 6 to 9 months. This will also help to improve some of the scars. This method however can be costly and is associated with side effects such as dry and peeling lips. Consult your doctor first before starting on any treatment.
