Rosacea (continued)

• Pathogenesis
  • This is not at all understood.  Since antibiotics (particularly tetracyclines) are effective therapy, a microbial contribution to pathogenesis has been considered but not proven. 
  • Similarly, agents triggering flushing (for example, alcohol) have been thought to at least aggravate rosacea, but it is not clear that this is the case.
    
    
• Diagnosis
  • As discussed previously, the presence of red papules and pustules in the central third of the face in the absence of comedones should suggest rosacea.
    
    
• Differential Diagnosis of Rosacea (see Table):
  • The rosacea variants are likely to cause most trouble. 
  • The telangiectatic variant may be confused with photo damage, and the often described but rarely seen "butterfly" rash of lupus.