PEDIATRIC DERMATOLOGY

April 1, 1999

Two days after the onset of fever and sore throat, a toddler developed painful lumps on his chest.

PEDIATRIC DERMATOLOGY

Jump to:Choose article section...What's your DX?Discussion

What's your DX?

By Bernard A. Cohen, MD

Two days after the onset of fever and sore throat, a toddler developedpainful lumps on his chest. When you evaluate him in your office the nextday, you note three tender violaceous nodules on his chest and a fever of38.2° C. His mother tells you the nodules have not changed since theyerupted over 24 hours earlier.

The rest of the examination is normal except for a fiery red pharynxand tender cervical adenopathy. A rapid strep screen from a nasopharyngealswab is positive, and you start the boy on a 10-day course of amoxicillin.

1. At what anatomic site in the skin would you expect to find the pathology?Near the surface in the epidermis or superficial dermis, or deep in thedermis or subcutaneous fat?

2. What is your diagnosis for the nodules on the chest?

3. What is the course of these nodules?

Discussion

Erythema nodosumis characterized by the sudden eruption of symmetricdeep, tender, red, warm nodules and plaques, usually between one and 10cm in diameter.1­3 Lesions typically appear on the shins,ankles, and feet of adolescents and young adults, but they can also involvethe arms, face, and trunk at any age, as in this toddler. At first theyare slightly elevated, but after several days, they flatten and developa purplish or livid color. Finally they fade to yellowish or greenish, suggestingdeep bruising. The peak incidence in childhood is in girls during adolescenceand boys between 10 and 14 years of age. Erythema nodosum is rare in childrenunder 2 years old.

Origin. Erythema nodosum is a reactive process in the fat rather thana specific disorder. Several things can trigger it, including drugs, infections,and systemic disease. In children, the most common trigger is a streptococcalinfection,2,3 though viral infections, histoplasmosis, coccidioidomycosis,and tuberculosis have also been implicated. Many drugs are reported to causeerythema nodosum, most commonly sulfonamides and birth control pills. Systemicinflammatory disorders that have been associated with erythema nodosum includesarcoidosis, Crohn's disease, connective tissue disease, and malignancyhave also been associated with erythema nodosum.1

Diagnosis. Skin biopsy of a chest lesion in this patient showed a septalpanniculitis diagnostic of erythema nodosum. Nodules sent for biopsy earlyin the illness usually demonstrate mixed inflammation--lymphocytes, neutrophils,and granulomas in fat septa, associated with edema and hemorrhage.4

Giant cells, lymphocytes, and fibrosis predominate late in the course,when vasodilation and sparse perivascular lymphocytic infiltration occurin the deep dermis.

The biopsy helps exclude cellulitis, which is usually more superficialand progressive. Insect bite hypersensitivity reactions cause pruritus andoften show a central punctum. Processes involving the subcutaneous fat mayalso be confused with erythema nodosum. The distribution of the nodules,clinical findings, and histology can be used to distinguish panniculitisassociated with lupus erythematosus, pancreatitis, trauma, cold-inducedinjury, and steroid withdrawal from erythema nodosum.

Resolution. The lesions usually heal in three to six weeks, but occasionallypersist for longer, or recur.1­3 After three days of amoxicillinthe child described here was back to normal without fever or sore throat,and the chest nodules were flattening. The eruption was completely clearfive days later and has not recurred.

The next installment of "Pediatric Dermatology: What's your DX?"will appear in July.

THE AUTHOR is Director, Pediatric Dermatology and Cutaneous Laser Center,and Associate Professor of Pediatrics and Dermatology at Johns Hopkins UniversitySchool of Medicine, Baltimore. He is a Contributing Editor for ContemporaryPediatrics.

REFERENCES

1.White JM Jr: Erythema nodosum. Dermatol Clin 1985;3:119

2. Hassink RI, Pasquinell-Egli LE, Jacomella V, et al: Conditions currentlyassociated with erythema nodosum in Swiss children. Eur J Pediatr 1997;156:851

3. Labbe L, Perel Y, Maleville J, et al: Erythema nodosum in childrenin a study of 27 patients. Pediatr Dermatol 1996;13:447

4. Ackerman AB: Histologic Diagnosis of Inflammatory Skin Disease. Philadelphia,PA, Lea and Febiger 1978, pp 779­825