From the Guidelines
Spider bites can be at risk for MRSA infection, though many suspected "spider bites" are actually MRSA skin infections misdiagnosed. If you have a skin wound from a suspected spider bite, keep it clean with soap and water, apply an antibiotic ointment like mupirocin, and cover with a clean bandage. Watch for signs of infection such as increasing redness, warmth, swelling, pus, or fever. If these develop, seek medical attention promptly as prescription antibiotics may be needed. For confirmed MRSA infections, healthcare providers typically prescribe antibiotics like trimethoprim-sulfamethoxazole (Bactrim), doxycycline, or clindamycin for 7-10 days, as recommended by the Infectious Diseases Society of America in their 2014 guidelines 1. Some infections may require drainage of pus collections. MRSA bacteria are commonly found on skin and can enter through any break in the skin barrier, including spider bites. The bacteria are resistant to common antibiotics like methicillin and other penicillins, making infections more difficult to treat and potentially more serious if not addressed promptly.
Key considerations for managing suspected spider bites and potential MRSA infections include:
- Keeping the wound clean and applying antibiotic ointment
- Monitoring for signs of infection
- Seeking medical attention if infection is suspected
- Using antibiotics effective against MRSA, such as trimethoprim-sulfamethoxazole, doxycycline, or clindamycin, as recommended by the Infectious Diseases Society of America 1
- Considering drainage of pus collections if necessary
It's essential to note that the guidelines for managing skin and soft tissue infections, including those caused by MRSA, have been updated, and the most recent recommendations should be followed, as outlined in the 2014 update by the Infectious Diseases Society of America 1.
From the Research
Spider Bites and MRSA Infection
- There is no direct evidence to suggest that spider bites are more likely to cause Methicillin-resistant Staphylococcus aureus (MRSA) infection 2, 3, 4.
- Spider bites can cause a range of symptoms, from minor local irritation to significant morbidity and mortality, but most species cause minimal or no effects 5, 6.
- MRSA is a common cause of skin and soft tissue infections, but it is not typically associated with spider bites 2, 3, 4.
- In Australia, skin ulceration is more likely to be an infective, inflammatory, or traumatic cause than a case of necrotising arachnidism, which is a condition caused by certain spider bites 5.
- Treatment of MRSA infections typically involves antibiotics, and several common antibiotics retain activity against different strains of MRSA 2, 3, 4.
- It is essential to consider spider bites in the differential diagnosis of unexplained autonomic and neurological dysfunction, particularly in children, but there is no direct link to MRSA infection 5, 6.