In principle, there are two types of medicinal therapy. They are prescribed according to the degree of acne severity.

• Local therapy: primarily includes the use of vitamin A derivatives and benzoyl peroxide drugs. These pharma-ceuticals, however, often dry out the skin. In addition, local antibiotics can be used, such as tetracycline (which can induce increased UV sensitivity) or erythromycin. This type of therapy is effective against the pathophysiologically important Propioni bacteria and against pathogens causing secondary infections – it can, however, cause bacterial resistance.
• Systemic (internal) therapy: for severe therapy-resistant acne, treatment with antibiotics or isotretinoin may be necessary. For women, contraceptives containing estrogen and anti-androgen-effective progestogens may be prescribed.