Diagnosis of Acne

• The presence of inflammatory skin lesions in the usual acne areas of face, chest, and back should arouse clinical suspicion, but the diagnosis cannot be made in the absence of comedones and these should be sought carefully.

Differential Diagnosis (see Table):

• Comedones without inflammation are seen in the severely photo damaged facial skin.  
• Inflammation without comedone formation (except possibly the nose) occurs in rosacea.