[Rosacea: Clinical features and classification].

Rosacea is a frequent chronic dermatological disorder mainly affecting the face. Since it affects the appearance, it can be very distressing for the patient leading to psychosocial disturbances. Rosacea occurs in adults, peaking between 40 and 50 years of age. The course of rosacea is quite variable and the disease may stop at any stage. Generally, three main stages are differentiated: erythemato-teleangiectatic rosacea (rosacea stage I), papulopustular rosacea (rosacea stage II), hyperglandular-hypertrophic rosacea (rosacea stage III). Besides these main manifestations numerous special forms exist, which often lead to difficulties in the differential diagnoses and require specific therapeutic strategies. These include rosacea conglobata, rosacea fulminans, granulomatous rosacea, persisting edema, (Morbihan disease), gram negative rosacea, ocular rosacea, and steroid rosacea. Recently increasing numbers of patients have been observed, whose rosacea was were induced by inhibitors of epidermal growth factors (cetuximab, geftinib) used as chemotherapy in patients with different malignancies. These side effects have been described as acneiform eruptions but at least some of the described patients have a rosacea-like appearance; therefore, this form can be classified as a subset of drug induced rosacea.