DermaDiagnosis

An Agreeable Girl With a Stubborn Rash

Clinician Reviews. 2016 September;26(9):15-16
Author(s):
Joe R. Monroe, MPAS, PA
Author and Disclosure Information
PDF Download

Distraught parents of a 5-year-old girl are at their wit’s end dealing with their daughter’s perioral rash, which first appeared several months ago. Although they’ve consulted three different primary care providers, who rendered several diagnoses and numerous treatments, the rash continues to worsen. The parents worry about scarring, but they are more concerned that the rash may never clear at all.

Her treatments have included oral erythromycin, oral amoxicillin, topical anti-yeast cream, and various petroleum-based and hydrocortisone-containing OTC lip balms. In a moment of desperation, the parents even applied their son’s psoriasis cream (betamethasone) and diaper cream. These, too, had no effect.

Contactants had been considered as a possible source, causing the family to switch toothpaste brands and toothbrushes and eliminate mouthwash use—again, with no change.

Family history includes an atopic brother (eczema, asthma, seasonal allergies). The parents confirm that the patient has very sensitive skin and can’t tolerate many soaps and moisturizers. Before the rash manifested, they noticed she had a tendency to compulsively lick her lips.

The patient is quite fair-skinned, with red hair and blue eyes. The rash, which covers her entire perioral area, is impressively florid, red, and scaly. Focally, several areas of honey-colored crusts can be seen. The vermillion surfaces of the lips are unaffected except for slight focal fissuring. No nodes can be felt in the head or neck. The patient is in good spirits despite all this, and certainly not in any distress.

The most likely diagnosis is

a) Impetigo

b) Yeast infection

c) Eczema

d) Psoriasis

ANSWER
The correct answer is impetigo (choice “a”). Impetigo is almost always secondary to another condition, such as contact or irritant dermatitis, eczema, or dry skin.

DISCUSSION
Impetigo is a superficial bacterial infection usually caused by a combination of strep and staph organisms. It requires a break in the skin to provide a point of entry for the organisms. In young children, scratching and picking at eczema, along with lip licking, exacerbate the barrier-breaching process.

The organisms that cause impetigo are typically benign, but this was not always the case. Prior to WWI, certain strains of strep were capable of triggering an immune response that resulted in kidney damage. These “nephritogenic” strains of the Streptococcus family caused acute post-streptococcal glomerulonephritis (Bright disease), which, at that time, killed thousands each year. Fortunately, these strains are rare now.

In the pre-antibiotic days, when the average person bathed once a week, impetigo was highly contagious and serious enough that whole households were quarantined because of it.

Today, impetigo, once diagnosed, is relatively simple to manage. Mild cases can be treated with application of mupirocin ointment or cream three times a day. In this particular case, a 10-day course of an oral antibiotic (trimethoprim sulfa) was added, and the rash rapidly cleared.

Next Article:

How to Nail the Diagnosis

Related Articles