Cystic acne is the most severe form of acne vulgaris and can be caused by a variety of factors. This type of acne sees painful lesions develop deep within the skin, which could result in permanent scarring or hyperpigmentation. Cystic acne is easily diagnosed due it its pronounced, inflamed lesions. However, you should consult a dermatologist to rule out other skin conditions which might mimic acne such as rosacea, psoriasis or perioral dermatitis.
Many different treatments exist for acne. These include alpha hydroxy acid, anti-androgen medications, antibiotics, antiseborrheic medications, azelaic acid, benzoyl peroxide, hormonal treatments, keratolytic soaps, nicotinamide, retinoids, and salicylic acid.[75] They are believed to work in at least four different ways, including the following: reducing inflammation, hormonal manipulation, killing P. acnes, and normalizing skin cell shedding and sebum production in the pore to prevent blockage.[76] Common treatments include topical therapies such as antibiotics, benzoyl peroxide, and retinoids, and systemic therapies including antibiotics, hormonal agents, and oral retinoids.[20][77]

How to Handle It: If you've tried the usual anti-acne ingredients, like salicylic acid and benzoyl peroxide (which, we should warn you, rarely work for this), you should consider paying your dermatologist a visit. "You may need a cortisone injection or an oral medication, like an antibiotic, in addition to topical formulas," says Zeichner. He's also a fan of a prescription topical medication called Epiduo Forte Gel, since, he says, it's been shown to be effective at controlling severe acne without the help of oral treatments.

Diet. Studies indicate that certain dietary factors, including skim milk and carbohydrate-rich foods — such as bread, bagels and chips — may worsen acne. Chocolate has long been suspected of making acne worse. A small study of 14 men with acne showed that eating chocolate was related to a worsening of symptoms. Further study is needed to examine why this happens and whether people with acne would benefit from following specific dietary restrictions.