This article is more than 5 years old. Information may no longer be current.
A 10-month-old boy with salmonella, rash
Click Here to Manage Email Alerts
A 10-month-old boy was in the hospital being treated for salmonella osteomyelitis of the scapula when near the end of his course of therapy, a rash developed. He had an excellent response to the ceftriaxone that was being used for intravenous antimicrobial therapy for his osteomyelitis, and was clinically well when the rash began. He remained well with no fever or any new complaints except mild itching, which did not interfere with his play or other activities. His appetite remained good and he otherwise had no new symptoms.
Pediatric Infectious Disease, Scott and White's Children's Health Center and Associate Professor of Pediatrics,
Texas A&M University, College of Medicine, Temple, Texas.
e-mail: jhbrien@aol.com
On examination, he was a happy baby with normal vital signs, and his exam was also normal except for the rash, which was a maculopapular rash with a general distribution, containing numerous annular lesions, some with purplish-gray centers, as shown in figures 1 – 5. There was no mucous membrane inflammation of the eyes, lips, mouth or urethra, or other positive findings.
No lab tests were done for the rash, but periodic testing of CBC’s, metabolic profiles, C-reactive proteins and urinalyses has all recently been normal.
What’s Your Diagnosis?
- Erythema Multiforme
- Kawasaki Disease
- Urticaria
- Stevens-Johnson Syndrome
Answer
You may be asking yourself, “Why would Dr. Brien use such a simple case for his normally complex and fascinating column?” And I can certainly appreciate that. But while to some this case may seem rather simple, for many it apparently is not, in that this condition is frequently misdiagnosed. This is urticaria (C), but was initially thought to be Erythema Multiforme, mainly because of the annular nature of some of the lesions with their dark centers, or the giant “multiforme” appearance of others. It is a fairly common condition that was probably caused by the antimicrobial that the patient had been receiving, although it could be from any number of other triggers. In addition to the typical erythematous, plaque-like appearance, another of the key features is the transient nature of individual lesions. It is very uncommon for mucous membranes to be involved, which may result in possible respiratory compromise. However, it is not uncommon to see some degree of angioedema, manifested as swelling of the eyelids, hands or feet. When there are immune complexes involved, causing joint symptoms, myalgias and fever, it is usually referred to as a serum sickness reaction, as shown in figure 6.
Most experts recommend treating urticaria with an over-the-counter H2-blocker such as diphenhydramine or chlorpheniramine or an Rx product like cetirizine or hydroxyzine. If this does not work, an H2-blocker, such as cimetidine or a combination of the two, may work. If this does not work, I would recommend referring the patient to a dermatologist.
Erythema Multiforme (EM) is a much less common condition, that is characterized by discrete papular lesions that are “fixed” (do not move around), and may develop a target-like appearance with a necrotic center over a few days (figure 7). Many children have a history of a preceding or current herpes simplex infection (figures 8-10), while others have been associated with other viral or mycoplasma infections. The lips can be involved, sometimes making it difficult to distinguish EM from Stevens-Johnson syndrome (SJS). Therapy is primarily symptomatic, although some experts use acyclovir due to the high association with herpes simplex, especially if chronic or recurrent.
As noted, SJS is an acute inflammatory condition affecting the skin and, by at least one definition, two or more mucous membrane surfaces, such as the eyes and oral mucosa/lips (figure 11-acute & 12-recovery in same patient). The cutaneous lesions may occasionally appear similar to EM lesions, but usually there’s more diffuse skin involvement with small, fluid-filled lesions (figure 13). However, in some patients, the skin lesions may be larger to more Bullous-like (figure 14). Most patients have a recent history of a viral infection, but there’s no consistent cause. Treatment is supportive, possibly requiring a burn unit. Obviously, if triggered by a drug, then the drug should be discontinued. There are anecdotal data for the use of steroids and IV immunoglobulin, but there are no scientific, evidence-based data for their use that I have seen.
Kawasaki Disease (KD) commonly has a polymorphous rash (figure 15), which may be indistinguishable from some cases of urticaria or EM. However, SJS, with its vesicular/Bullous-containing lesions are usually easy to distinguish from the rash of KD. Also, KD will likely have other findings, such as a non-exudative conjunctivitis (figure 16), other mucous membrane inflammation, swelling of the hands and/or feet (figure 17) or lymphadenopathy.
Finally, once you learn to recognize the typical appearance of annular and giant urticaria, and understand the difference between the fixed lesions of EM and the transient nature of urticaria, it is usually easy to distinguish the difference visually. However, there’s one other clinical feature that I have noticed over the years; in both EM and SJS, patients tend to be sicker, whereas urticaria patients are usually happy, normal-acting children. It’s very unusual to see a child with either EM or SJS with a smile like that shown in figure 1 above or figures 18 & 19, a little friend of mine with urticaria.
This is a fairly brief and simple description of some very complex vascular exanthems. To see some excellent pictures and read an in-depth review of urticaria, erythema multiforme and SJS, including therapy, I would recommend Chapter 19 by William Weston and David Orchard, in Schachner and Hansen’s Pediatric Dermatology, 3rd Edition (2003) textbook (Mosby). Much of the research for this column on these conditions was obtained in this great, comprehensive textbook, which also comes with a CD with all the pictures in a downloadable format.
Columnist Comments
The 43rd Annual Uniformed Services Pediatric Seminar (USPS) will be held March 8 – 11, 2009 at the Hyatt Regency in Indianapolis, Indiana. This is always an outstanding AAP-sponsored CME opportunity. You don’t have to be a Military or Public Health Corps Pediatrician to attend. Also, the USPS is likely to be the only meeting you will ever attend with military-style opening and closing ceremonies, complete with the singing of each of the Service Songs during the opening ceremony.
The web site to see the brochure and learn more about this great meeting is: http://www.pedialink.org/cmefinder/brochures/2009%20USPS%20Brochure.pdf.
The first USPS meeting I attended was the 14th Annual Pediatric Tri-Service Meeting, as it was called in those days before including the U. S. Public Health Corps. Unfortunately, due to scheduling problems, I will be unable to attend the USPS next March. Otherwise, I would not miss it. However, I will definitely be at the 44th Annual USPS in March 2010 in San Diego. Hopefully, I will see you there.
Happy Holidays from the Brien family to yours, and please think of our troops (and fellow Pediatricians-in-arms) during this holiday season. It is an especially difficult time to be away from home and family, whether you’re being shot at or not.