resistant Staphylococcus aureus or MRSA
(False spider bite diagnosis):
In the last 2 years
clinicians have noticed a gross increase in MRSA. This author
has personally noticed an enormous increase in this diagnosis
in the last 7-10 months in the Northern Illinois area. Some
speculate that the reason is due to the fact that clinicians
are culturing wounds more frequently. Others believe that
this is an emerging disease state.
Staphylococcus aureus is a very common organism. We are seeing
an increase in the Methicillin resistant strain. Typical culture
and sensitivity results on Methicillin resistant Staphylococcus
Amox-Clavulanate - resistant
Cephalosporins - resistant
Ciprofloxacin - sensitive
Clindamycin - sensitive
Erythromycin - sensitive
Gentamicin - sensitive
Levofloxacin - sensitive
Penicillin - resistant
Rifampin - sensitive
Trimethoprim/sulfa - sensitive
Vancomycin - sensitive
Signs & symptoms of MRSA
Side note: Rifampin should not be used alone for chemotherapy.
Please consult Sanford guidelines.
When these lesions present, they are usually very red. They
can be the size of a quarter, half dollar or silver dollar.
They are commonly found on the extremities. They are indurated
and can be fluctuant to touch. It appears to look like abscesses
or a spider bite. Very commonly confused with a spider bite.
They may be ulcerating in the center. They can occur in anyone
in the population. I have seen them on young children playing
soccer. They can be passed between different family members.
It is not uncommon for the MRSA organism to colonize in the
Healthcare provider treatment
- Do not diagnose a spider bite if you
are unsure and the person does not bring in or see the spider
- Look at the geographical location. If
you are in northern sections of the United States, it is
very unlikely that you are going to be bitten by a brown
recluse spider. Brown recluse spiders are more prevalent
in the South and in warmer climates.
- These wounds should be I & D'd. C
& S (culture & sensitivity) needs to be performed
on all of the individuals can be started on a Cephalosporin.
However if you are questioning a MRSA diagnosis, you can
go ahead and start the patient on Ciprofloxin.
- After consulting with an infectious disease
specialist, they advise that once MRSA has been diagnosed,
never prescribe Ciprofloxin alone. Use in combination with
In cases of recurrent MRSA in the same patient or household,
Chlorohexadine sponge baths twice a day for a week, all
chairs, couches, bed linens, sheets, even the car headrests
and seats need to be cleaned.
- Bactroban Mupirocin cream should be used
intranasally twice a day for 5 days, as well as the combination
chemotherapy as previously discussed. Close follow-up is
imperative with frequent wound care and packing.
- Close observation for lymphangitis is
important in acceleration of the infection.
Once again, be careful not to confuse these with spider bites.