First, we'll cover non-bullous impetigo. This is the most common. The patient will have a red
sore near the nose or mouth and it's going to start to leak pus or fluid. Then the patient will
form a honey-colored scab or a honey-colored crust and this is the classic symptom. Then this
will heal. The patient typically doesn’t have a lot of pain, but they will come in saying their
lesion is itchy. They may have lymphadenopathy and this is the body's response to the
infection and this can be spread easily to other parts of the body. Now we'll cover bullous
impetigo. These are painless bullae which is a collection of big blisters created by the toxins
produced by the Staph bacteria. We find this commonly in skinfolds including the axilla, the
groin, between the fingers, and between the buttocks. This is red and itchy and is also a
painless condition. And after these blisters break, the patient will form these yellow scabs.
So, on exam, we want to collect a full health history and check your patient's vital signs.
Next, you'll do a cardiac and respiratory exam and then focus on their skin. Remember you
also want to check the patient's lymph system because they can have lymphadenopathy due
to this infection. How do we diagnose impetigo? It's usually diagnosed based on the clinical
exam. It's classic with this honey-colored crust. It's going to be found on the face, the arms
or the legs, can be anywhere on the body though and you can do a bacterial culture but this
is not always necessary because remember it's usually caused by Staph or Strep. So, the
differential diagnoses, things that can look like impetigo but are not include contact dermatitis,
herpes simplex virus. Remember always have that on your differential was this a primary
herpetic lesion that is now secondarily infected, patients with discoid lupus and also scabies.
Now while we can treat impetigo, we also want to try to prevent the spread because it's very
contagious. Patients want to keep their wounds clean and covered and practice strict handwashing.
You'd like your patients to keep their nails short so they reduce scratching and don't share
clothing or linens. Patients can return to school or work after they've been on antibiotics for
24 hours and we want them to cover their lesions if they're draining. So we treat impetigo with
antibiotics and typically topicals work including mupirocin but the patient may have a large
surface area of impetigo. And they may need oral medication including dicloxacillin,
erythromycin, augmentin, and the first generation cephalosporins. Now these are effective
for methicillin-sensitive Staph aureus but if the patient has methicillin-resistant Staph aureus
or MRSA, you'll have to treat with a different agent including doxycycline, clindamycin, or
trimethoprim-sulfamethoxazole. Now remember your patient can have a secondary impetigo
after a primary herpetic lesion so remember your patient may also need antivirals. There
are a few complications to impetigo and it usually self-resolves in a few weeks, but the
patient can develop a deeper skin infection called cellulitis and this can spread to the lymph
nodes and the bloodstream. Your patient can also develop post-Strep glomerulonephritis and
this is secondary to the Strep bacteria. Also there's Staph scalded skin syndrome and this is
an illness characterized by red blistering skin that looks like a burn or a scald, hence its name.
Staph scalded skin syndrome is caused by the release of 2 exotoxins from the toxigenic strains
of the Staph bacteria. Here is an example of the Staph scalded skin syndrome, and you can see
the toxin lifts up the layers of the skin causing it to slough or peel off and these patients are
managed at a burn center. The patient can also get scarring from their lesions and so you
want to encourage them not to scratch.