THE CASE
Fearful frustrated parents deliver their ill-appearing 16-year-old daughter to your office for evaluation of persistent painful
papules and plaques associated with high fever, sore throat, and arthralgias. The eruption first appeared on the distal extremities
three days ago, and has now disseminated to the proximal extremities and trunk (Figures 1 and 2). She was sent home from the emergency department yesterday with instructions to take plenty of fluids and ibuprofen.
DIAGNOSIS:
Diagnosis: Sweet's syndromeSweet's syndrome, also known as acute febrile neutrophilic dermatosis, is a reaction pattern in the skin characterized by
a neutrophilic infiltrate. This may present in several forms, including:1
Classical Sweet's syndrome (CSS) is often preceded by a streptococcal or viral upper respiratory tract infection, and is
occasionally associated with inflammatory bowel disease or pregnancy.
Malignancy-associated Sweet's syndrome (MASS) occurs in the context of a patient with an occult solid tumor or a hematologic
dyscrasia, most commonly acute myeloid leukemia.
Drug-induced Sweet's syndrome (DISS) is most commonly triggered by granulocyte colony stimulating factor (GCSF) or the antibiotic
sulfamethoxazole-trimethoprim.2,3
CLINICAL FINDINGS
Figure 3 Hematoxylin-eosin stain: diffuse dermal infiltrate composed of neutrophils and nuclear debris (without evidence of
vasculitis). Image courtesy of Lisa M. Cohen, MD at Caris Cohen Dx
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Children with Sweet's syndrome appear ill with acute onset of high fever, painful papules and nodules, arthralgias, and no
apparent source of infection.1-6 The skin eruption, which most commonly develops on the face and extremities and may spread to the trunk, is characterized
by tender, erythematous to violaceous, round to annular papules and plaques.2,3 Vesicles and pustules that may appear at the periphery of the enlarging plaques usually do not become frankly bullous or
ulcerate. Healing occurs without scarring.1 Extracutaneous manifestations of Sweet's syndrome may affect virtually every body system. Peripheral leukocytosis with neutrophilia,
an elevated erythrocyte sedimentation rate, and C-reactive protein are frequently seen.1,3DIFFERENTIAL DIAGNOSIS OF NODULAR RASH
Erythema nodosum is another reactive erythema that may also be triggered by infections, drugs, inflammatory diseases, lymphomas,
and pregnancy. Deep-seated painful, erythematous to violaceous nodules develop typically on the anterior surface of both legs,
and usually resolve in two to eight weeks without scarring. The eruption of Sweet's syndrome can be clinically and histologically
distinguished from erythema nodosum, which is an inflammatory disorder involving fat.
Disseminated gonococcemia begins with papules and vesicles, which may occasionally evolve to pustules with a necrotic base.
It may also be associated with fever and polyarthritis. A Gram stain obtained after unroofing a pustule reveals the organism.
Rheumatoid neutrophilic dermatitis (RND) occurs most frequently in women with seropositive rheumatoid arthritis (RA). The
typical eruption consists of erythematous, urticarial-like papules, plaques or nodules less than two centimeters in diameter.
Unlike Sweet's syndrome, lesions in RND usually clear with aggressive treatment of the RA. Moreover, these patients do not
present with fever or other constitutional symptoms.
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