Wednesday, July 22, 2015

Confluent Rash on a Child

Confluent Rash on a Child

Case presentation: A 2-year-old boy with no medical history presents to the emergency department with complaints of a diffuse rash over his bilateral lower extremities for the past 2 days that is now progressing to his trunk and upper extremities. He otherwise appears playful and well with no complaint of itching or fever. His parents deny new detergents, creams, or drug exposures. They do, however, report mild upper respiratory symptoms 1 week ago. 

On physical examination, he has multiple confluent lesions with central clearing diffusely. The lesions are present on his palms and soles but are most prominent on his bilateral lower extremities. There is no conjunctival injection, and there are no sores in or around his mouth or genital area.

Question: What is the next most appropriate management
strategy at this time?

A. Obtain a complete blood count (CBC) and blood culture, administer ceftriaxone, and admit for
B. Obtain a CBC and blood culture, but do not treat with antibiotics
C. Discharge to home with diphenhydramine as needed for itching
D. Consult dermatology emergently
E. Administer subcutaneous epinephrine immediately

confluent rash whole over the body 

Answer: C
Diagnosis: Erythema multiforme (minor)
Discussion: Erythema multiforme (EM) is an acute and typically self - limited hypersensitivity reaction that manifests as a diffuse eruption with characteristic lesions. The  lesions are usually symmetric, involve the palms of the hands and the soles of the feet, and predominate on the
extensor surfaces of the upper and lower extremities.
Although these are characteristic locations, lesions can be found anywhere on the body. The rash of EM can look macular, urticarial, or vesicobullous, but the prototypical  lesion is a target lesion with a dusky center. Often the rash changes from one form of lesion to another as the disease progresses. The rash itself generally lasts for at least 1 week, but can last up to 6 weeks. Patients are often otherwise asymptomatic, although they can also have itching associated with the lesions or involvement of the oral mucosa.  The causes of EM in children are most commonly infectious,
whereas in adults the condition is much more frequently related to drug reaction or malignancy. The most common infectious agent attributed to EM is herpes simplex virus. The differential diagnosis of EM includes pemphigus, bullous pemphigoid, urticaria, or other viral exanthems. Treatment for EM minor may involve cessation of inciting agents but is mainly supportive, including antihistamines and/or nonsteroidal anti - infl ammatory drugs. Systemic glucocorticoids are sometimes used, although there are no randomized trials showing clear  benefi t. Recurrent cases may be treated with antiviral medications including acyclovir, valacyclovir, or  famciclovir.

 Classically, EM has been thought to be part of continuum of more serious illness such as Stevens – Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), but increasingly EM is being considered a distinct diagnosis, albeit with a similar pathophysiology to that of the more  severe syndromes. It is important on physical examination to evaluate mucosal surfaces to differentiate between EM and SJS or TEN. EM involves the skin and only one other mucosal surface, usually the mouth. In contrast, SJS involves the eye, oral cavity, genital mucosa, upper airway, or esophagus. SJS and TEN are much more serious conditions with signifi cantly higher mortality rates. 

Treatment for these conditions is frequently compared to burn care, and hospital admission is required. It is important to keep these other entities in mind even in cases of EM because patients and their families should be discharged with clear instructions about signs to look for that may indicate progression to more serious disease.


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