Dr. Kadile, I think I got bit by a spider, but my friend thinks the lesions on my arm are from a Mersa infection. What is Mersa?

-Elwood, DHS

Elwood, I believe you are referring to an infection caused by Methicillin-resistant Stapylococcus aureus. (MRSA).  I commonly see patients with skin lesions that can look like an insect or spider bite, but unless you actually see the insect or spider, the lesions may be caused by a bacterial infection.  MRSA  is a result of antibiotic overuse that has caused the bacteria to be resistant to commonly used antibiotics. The MRSA infection that involves the skin is most commonly acquired within the general community (Community acquired). If you were in the hospital, you may have been infected by MRSA that can cause pneumonia (Hospital acquired). In order to identify if skin lesions are due to MRSA, a culture of drainage coming from the lesions would need to be performed.

MRSA lesions can appear like small red and inflamed pimples or bites. The area is generally warm to the touch and may be slightly tender. A fever may be present. If the lesions are not treated with an antibiotic that it is sensitive to, an abscess may develop that may requires surgical draining. The bacteria can even cause deep infections to the bones, joints, heart, lungs and bloodstream.


If you suspect you have a MRSA infection, have your physician evaluate the skin lesions and obtain a culture. If the culture results are positive for Methicillin-resistant Staph aureus, additional testing would be performed to determine if any antibiotics could be used for treatment.

Hey Doc, I have a sore throat, runny nose and a cough. How do I know I don’t have strep throat?

Mark, Morongo Valley

Mark, the symptoms you are describing sound like the common cold. To verify you don’t have strep throat, a culture on your throat would need to be done. Strep throat is caused by the bacteria, Streptococcus pyogenes. Symptoms are generally a severe sore throat, “it hurts to swallow”, fever and swollen lymph nodes in the neck. Strep throat generally does not involve a cough or hoarse voice. Antibiotics are the treatment of choice, but strep throat may resolve without treatment. If antibiotics aren’t being used, the infected person can still be contagious for up to 3 weeks even if symptoms resolve. Strep is spread when an infected person coughs or sneezes on someone or shares food or drink.

Dr. Peter M. Kadile is Board Certified in Family Medicine. He has an integrative,
osteopathic medical practice and is also known as the local, house call doctor; Desert House Call Physician. He is on staff at Eisenhower Medical Center and medical director for Serenity Hospice. His office is located in beautiful Old Town La Quinta, 78-100 Main Street, Suite 207,La Quinta, CA 92253. (760) 777-7439. DesertHouseCalls@aol.com. deserthousecalldoc.com.