What is the cause of rheumatism and by what mechanism the disease develops? List the
diagnoses of the main organ lesions
RHEUMATISM = is a SYSTEMIC, RECURRENT, NON-SUPPURATIVE Allergic Inflammatory COMPLICATION of UNTREATED Pharyngeal Infection.
MECHANISM:
1) T-Cell Mediated Disease - Type II / III Hypersensitivity Reactions
2) Antibodies IgG / IgM are produced by the body against Group A Strepto M Protein + Carbs
3) There’s a CROSS-REACTION between Body Cells + Strep ANTIGENS
MAIN ORGAN LESIONS
a) HEART = Carditis / Pancarditis
b) JOINTS = Polyarthritis
- multiple, large asymmetrical joints that’s swollen, red, warm + painful
c) BASAL GANGLIA / BRAIN = Chorea Minor
- random INVOLUNTARY movements, that develop 6 months AFTER
d) ERYTHEMA MARGINATIUM & NODOSUM:
- EM = CIRCULAR red RING surrounding NORMAL Skin
- EN = NODULAR red TENDER RASH OVER ANTERIOR Tibia
e) SUBCUTANEOUS NODULES = Pea-Sized, NON-TENDER OVER BONY Prominences
- INDICATES Cardiac involvement
- GRANULOMATOUS Reaction W/ “Picket-like Organisation” of histocytes, SURROUNDING the foci of fibrinoid necrosis
Rheumatic myocarditis histology
RHEUMATIC MYOCARDITIS
0 Gross Appearance of Heart = MODEST Dilatation + MURAL Softening
0 Micro = MYOCYTE Necrosis + INTERSITIAL Chronic Inflammation
a. Granulomatous
- Presented by ASCHOFF BODIES in Heart INTERSTITIUM
- Perivascular AND Subendocardial LOCALISATION
- Found in Heart LONG AFTER Clinical Signs of Disease are RESOLVED
b. Diffuse Non-Specific Myocarditis
RHEUMATIC PERICARDITIS
- Prominent FIBRINOUS Pericarditis Present
- FIBROUS ORGANISATION of Pericardium
Evolution of Aschoff bodies (stages)
-point out the stages in rheumatic endocarditis
FOUND in Microscopic Lesions in RHEUMATIC CARDITIS
STAGES
1) EARLY Phase = EOSINOPHILLIC Fibres + INFLAMMATORY Infiltrate
2) INTERMEDIATE Phase = NECROSIS + Inflammatory CELLS
3) LATE Phase = 3 - 4 Months AFTER Onset!
Pannus definition and in what disease?
DEFINITION = Inflammatory PROCESS, causing THICKENING + HYPERPLASIA of SYNOVIUM, which GETS REPLACED by a Vascularised MASS (Pannus)
- Consists of Lymphocytes + Plasma Cells, surrounding areas of FIBRINOUS Necrosis, WITH PALISADING HISTOCYTES
- With the Pannus being POSITIONED IN BETWEEN Articular Surface LIMITS Joint Movement, leading to IMMOBILISATION of Joint
- Pannus UNDERGOES Fibrosis + Healing in RHEUMATOID ARTHRITIS
Describe the structure of granuloma in sarcoidosis
SARCOIDOSIS
- Granulomas DO NOT contain Necrosis
- Surrounded by FIBROSIS (aka Concentric Scar Tissue)
- Often contain:
0 STAR-SHAPED Structures (ASTEROID BODIES)
0 LAMELLAR Structures (SCHAUMANN BODIES)
