Pediatric Dermatology Vol. 15 No. 1 51-52, 1998

Unilateral Laterothoracic Exanthem in a Child with Acute Lymphoblastic Leukemia

Daniel W. Fort, M.D.,* and Kenneth E. Greer, M.D.?

Departments of *Pediatrics and fDermatology, University of Virginia, Charlottesville, Virginia

Abstract: Unilateral laterothoracic exanthem (ULE) is a rare childhood condition of unknown etiology characterized by a morbilliform rash that usually begins in the axilla and spreads centrifugally. The condition is usually self-limited, does not require specific treatment, and disappears within 4 to 6 weeks. Pruritus may be relieved by oral antihistamines and topical emollients and/or bath oils. We describe ULE in a 6-year-old girl with acute lymphoblastic leukemia, the first report of ULE in a patient with malignancy.

Unilateral laterothoracic exanthem (ULE), more re- cently termed asymmetric perifluxural exanthem of childhood (APEC) is a self-limited condition first de- scribed by Bodemer and de Prost (1-4). ULE is twice as common in girls as boys, with a mean age of onset of 24 months. Characteristic lesions are 1 mm erythematous papules that usually develop in the axilla or groin and spread centrifugally, sometimes extending into the groin. Individual papules coalesce, becoming erythematous scaling patches with a dusky center. Subsequently it may become bilateral, although the unilateral predominance is maintained in the majority of patients. The rash usually resolves spontaneously within 4 to 6 weeks (1,3,5). His- tologically ULE is characterized by an infiltrate of lym- phocytes which is often perivascular and may cluster around and infiltrate dermal eccrine ducts. The epidermis is characterized by mild exocytosis and spongiosis. No etiology for the condition has been determined, although a viral pathogen is suspected (1,3,.5). There is no reported association of ULE in patients with malignancy or other immunocompromised states. We describe a 6-year-old with acute lymphoblastic leukemia (ALL) and ULE.

CASE REPORT

A 6-year-old white girl with ALL diagnosed 6 months earlier who was in complete remission developed the characteristic clinical appearance of ULE. Onset of the rash occurred during the consolidation phase of antileu- kemic therapy which consisted of treatment over a 6- month period with methotrexate, 6-mercaptopurine, vin- cristine, prednisone, and intrathecally administered methotrexate, hydrocortisone, and cytosine arabinoside. Eight weeks prior to the onset of the rash she was treated with metronidazole for 10 days for diarrhea caused by Giardia lamblia. The rash began in the right axilla and spread centrifugally along the lateral thoracic wall to the inguinal area extending to the level of the knee. The rash remained unilateral until it completely resolved. Lesions consisted of 1 mm pruritic papules with a surrounding red halo. The eruption did not respond to 1% hydrocor- tisone cream, but resolved spontaneously in 4 months. Pruritus was treated with oral antihistamines and topical emollients. There were no systemic symptoms. Antileu- kemic therapy for ALL has been continued using metho-

Address correspondence to Daniel W. Fort, M.D., Department of Pediatrics, Box 386, University of Virginia, Charlottesville, VA 22908.

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52 Pediatric Dermatology Vol. 15 No. 1 JanuarylFebmary 1998

trexate and 6-mercaptopurine. There has been no evi- dence of exacerbation of the rash during periods of neutropenia or purpuric changes associated with throm- boc ytopenia.

DISCUSSION

This is the first report of a child with malignancy and ULE. Our case suggests that ULE in children treated for malignancy may be self-limited and unrelated to immune status. The distribution of ULE in our patient was similar to that in children without malignancy, but the duration of the rash was longer than that noted in previous reports (1,3-5). Our patient was treated for G. Zamblia prior to the onset of the rash. A similar association of diarrhea caused by Campylobacter jejuni preceeding the onset of rash was described by McCuaig et al. in two patients (5) . Maroon and Billingsley described a 14-month-old infant with an associated upper respiratory infection preceeding the onset of rash (6). Although a viral etiology has been postulated for ULE, none has been confirmed (1-5).

The benign course of ULE in our patient suggests that treatment for malignancy should not be withheld or de- layed in children who develop ULE.

REFERENCES

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Bodemer C, de Prost Y. Unilateral laterothoracic exanthem in children: 18 cases. Pediatr Derniatol 1992;9:208. Bodemer C, de Prost Y. Unilateral laterothoracic exanthem in children: a new disease? J Am Acad Dermatol 1992;27:

Mendelsohn S S , Verbov JL. Asymmetric periflexural ex- anthem of childhood. Clin Exp Dermatol 1994;19:421. Gelmetti C, Grimalt R, Cambiaghi S , et al. Asymmetric periflexural exanthem of childhood: report of two new cases. Pediatr Dermatol 1994; 1 1:42-45. McCuaig CC, Russo P, Powell J, et al. Unilateral latero- thoracic exanthem: a clinicopathologic study of forty-eight patients. J Am Acad Dermatol 1996;34:979-984. Maroon M, Billingsley EM. Unilateral laterothoracic ex- anthem [letter]. J Am Acad Dermatol 1993;29:130.

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