Juvenile rheumatoid arthritis (JRA) is a generalized systemic
disease of unknown etiology characterized by a transient macular,
papular, or urticarial rash and ensuing fever, lymphadenopathy, hepatosplenomegaly
(HSM), anemia, and arthralgia.
There are four classical evanescent eruptions: (1) urticaria,
(2) erythema marginatum (of acute rheumatic fever), (3) the rash
of Still disease, and (4) serum sickness.
JRA has three major types:
1. Systemic onset (20%): Still’s
disease, fevers, rash, lymphadenopathy (LAD), HSM, serositis, polyarthritis
2. Polyarticular (20%): >five joints, hands, feet >
3. Oligo-/Pauciarticular (60%): < four joints,
knees > ankles
Synonyms Still’s disease,
juvenile idiopathic arthritis, juvenile chronic arthritis.
Age Peaks: 2 to 4 years, adolescence.
Gender Systemic JRA: M = F.
Others: F > M, 2:1.
Genetics Polymorphisms for the
genes encoding tumor necrosis factor-α (TNF-α), migratory inhibitory factor,
interleukin-6 (IL-6), and tapasin (endoplasmic reticulum component
involved in antigen presentation).
Cytokines TNF-α, migratory inhibitory factor, and IL-6 parallel
the fever spikes, but the pathogenesis of JRA is still not understood.
JRA tends to be precipitated by emotional, infectious, or surgical
The onset of JRA may be sudden or insidious, depending on the
age of the patient (the younger the patient, the more severe the
systemic manifestations). Cutaneous eruptions occur in 90% of patients
and may be the initial presentation. The rash of JRA is evanescent
and can be macular or urticarial. Systemically, there may be associated
fever, adenopathy, splenomegaly, anemia, and arthralgias.
Type Macules, papules, urticarial
plaques (Fig. 17-1).
Juvenile rheumatoid arthritis Transient
macular rash on the leg of a young girl characteristic of juvenile
Color Salmon pink to red, with
a zone of pallor (Fig. 17-2).
Juvenile rheumatoid arthritis Faint
erythematous, urticarial plaques on the torso of a child.
Distribution Areas of trauma/heat:
axilla, waist, olecranon process/ulnar forearm, dorsal
hands, knees, ears, scapula, sacrum, buttocks, and heels.
Other Palms and soles: thenar and
hypothenar eminences may be erythematous. Periungual telangiectases
(5% of patients). Spindling fingers (50%, spindle-shaped
deformity of fingers because proximal interphalangeal involvement
> distal interphalangeal involvement).
single joint (knees > ankles/hips > hands), symmetric polyarthritis
joints, motion limitation (knees: 90%, fingers: 75%,