Function

• One form of psoriasis may be triggered by an infection from bacteria, especially strep throat. Known as guttate psoriasis, the outbreaks are marked by small red spots on the skin. It's common to use antibiotics to treat the underlying infection that causes the guttate outbreak. The antibiotics can help to control the initial infection and prevent its spread. Some dermatologists and general physicians also treat other forms of psoriasis with antibiotics (among other treatments). According to the National Institutes for Health, there is little evidence that this kind of antibiotic treatment has any medical value.
  
  

Expert Advice

• According to the Dermatology Centre at the University of Manchester, there is no solid evidence that antibiotics are useful in treating psoriasis. The Centre staff reviewed existing research studies to draw that conclusion. Antibiotics have been shown to interfere with other psoriasis treatments. The University of Michigan Health System warns that the frequently prescribed antibiotic tetracycline can block the function of acitretin, a powerful medicine proven to clear symptoms of psoriasis.
  
  

Risks

• Antibiotic resistance represents an example of survival of the fittest. Though antibiotics work to kill off bacteria, a small percentage of germs may survive. These germs pass on their resistance as they multiply. The long-term result is a new strain of bacteria that can't be killed off by existing antibiotics. Doctors and researchers now find themselves in a race to develop new treatments that can cope with stronger varieties of harmful bacteria. Antibiotic resistance has become one of medicine's most pressing problems. Psoriasis treatment serves as an example of how antibiotics may be overused without any clear evidence of effectiveness.
  
  

Alternatives

• Psoriasis outbreaks often make skin look red and irritated. It's easy to confuse these symptoms with an infection, leading some psoriasis patients to request antibiotics from their doctors. In fact, there are a number of other treatments that can be much more effective. These include topical lotions and ointments, steroids, biologic medications, light therapy and highly potent chemotherapy drugs. In addition, alternative treatments, such as dietary changes, herbal supplements, sea salts, acupuncture and more have been found effective for some psoriasis patients.
  
  

Misconceptions

• Cases of psoriasis linked to infections are actually rare. Most psoriasis cases have genetic or environmental causes. Although the exact mechanism that leads to outbreaks remains unknown, it's clear that the immune system in psoriasis patients is overactive. This causes the characteristic buildup of skin in the patient, leading to itching, flaking and other symptoms. Bacteria plays no part in this process, and so antibiotics have little effect in most cases.