Page 459 - Textbook of Pathology, 6th Edition

like tendons, ligaments, fascia or periosteum and therefore Histologically, the changes are oedema, capillary 443
often remain unnoticed by the patient. Characteristic haemorrhages and focal areas of fibrinous exudate in the
locations are extensor surfaces of the wrists, elbows, ankles alveoli. Aschoff bodies are generally not found.
and knees.
Histologically, the subcutaneous nodules of RF are CLINICAL FEATURES
representative of giant Aschoff bodies of the heart. They The first attack of acute RF generally appears 2 to 3 weeks
consist of 3 distinct zones: a central area with fibrinoid after streptococcal pharyngitis, most often in children
changes, surrounded by a zone of histiocytes and between the age of 5 to 15 years. With subsequent
fibroblasts forming a palisade arrangement, and the streptococcal pharyngitis, there is reactivation of the disease
outermost zone of connective tissue which is infiltrated and similar clinical manifestations appear with each recurrent
by non-specific chronic inflammatory cells and attack. The disease generally presents with migratory
proliferating blood vessels. polyarthritis and fever. However, RF has widespread
systemic involvement and no single specific laboratory
It may be mentioned here that histologically similar but
clinically different subcutaneous lesions appear in diagnostic test is available. As per revised WHO criteria
rheumatoid arthritis; they are larger, painful and tender and (2004) based on revised Jones’ criteria (first described by Dr.
persist for months to years (Chapter 28). TD Jones in 1944, and last revised in 1992), following major
and minor criteria are included for diagnosis:
3. ERYTHEMA MARGINATUM. This non-pruritic A. Major criteria:
erythematous rash is characteristic of RF. The lesions occur 1. Carditis
mainly on the trunk and proximal parts of the extremities. 2. Polyarthritis
The erythematous area develops central clearing and has 3. Chorea (Sydenham’s chorea)
slightly elevated red margins. The erythema is transient and 4. Erythema marginatum
migratory. 5. Subcutaneous nodules
4. RHEUMATIC ARTERITIS. Arteritis in RF involves not B. Minor criteria: CHAPTER 16
only the coronary arteries and the aorta but also occurs in 1. Fever
arteries of various other organs such as renal, mesenteric and 2. Arthralgia
cerebral arteries. The lesions in the coronaries are seen mainly 3. Previous history of RF
in the small intramyocardial branches. 4. Laboratory findings of elevated ESR, raised C-reactive
protein, and leucocytosis
Histologically, the lesions may be like those of 5. ECG finding of prolonged PR interval.
hypersensitivity angiitis (Chapter 15), or sometimes may
resemble polyarteritis nodosa. Occasionally, foci of C. Supportive evidence of preceding group A streptococcal The Heart
fibrinoid necrosis or ill-formed Aschoff bodies may be infection include: positive throat culture for group A
present close to the vessel wall. streptococci, raised titres of streptococcal antibodies
(antistreptolysin O and S, antistreptokinase, anti-strepto-
5. CHOREA MINOR. Chorea minor or Sydenham’s chorea hyaluronidase and anti DNAase B).
or Saint Vitus’ dance is a delayed manifestation of RF as a Clinical diagnosis of RF and RHD is made in a case with
result of involvement of the central nervous system. The antecedent laboratory evidence of streptococcal throat
condition is characterised by disordered and involuntary infection in the presence of any two of the major criteria, or
jerky movements of the trunk and the extremities occurrence of one major and two minor criteria.
accompanied by some degree of emotional instability. The If the heart is spared in a case of acute RF, the patient
condition occurs more often in younger age, particularly in may have complete recovery without any sequelae. However,
girls. once the heart is involved, it is often associated with
reactivation and recurrences of the disease. Myocarditis, in
Histologically, the lesions are located in the cerebral particular, is the most life-threatening due to involvement
hemispheres, brainstem and the basal ganglia. They of the conduction system of the heart and results in serious
consist of small haemorrhages, oedema and perivascular arrhythmias. The long-term sequelae or stigmata are the
infiltration of lymphocytes. There may be endarteritis chronic valvular deformities, especially the mitral stenosis,
obliterans and thrombosis of cortical and meningeal as already explained on page 441. Initially, a state of
vessels. compensation occurs, while later decompensation of the heart
leads to full-blown cardiac failure. Currently, surgical
6. RHEUMATIC PNEUMONITIS AND PLEURITIS. replacement of the damaged valves can alter the clinical
Involvement of the lungs and pleura occurs rarely in RF. course of the disease.
Pleuritis is often accompanied with serofibrinous pleural The major causes of death in RHD are cardiac failure,
effusion but definite Aschoff bodies are not present. In bacterial endocarditis and embolism:
rheumatic pneumonitis, the lungs are large, firm and 1. Cardiac failure is the most common cause of death from
rubbery. RHD. In young patients, cardiac failure occurs due to the