Pearls
↓ complement
1. SLE (low C3, C4)
2. Sjögren
3. cryoglobulinemia (types II & III, with RF) (low C3, C4)
4. HBV / HCV
5. HUVS (HBV and C1q autoantibodies)
6. Endocarditis (immune-complexes)
7. post-streptococcal GN (antigens activate alternative pathway, only ↓C3)
8. membranoproliferative GN (C3-DDD)
9. IgG4-RD (tubulointerstitial nephritis) (low C3)
DIP arthritis
1. seronegative
2. OA
3. multicentric reticulohistiocytosis (erosive)
4. gout (tophaceous)
5. PBC
p-ANCA
(other than AAV)
1. drug-induced: propylthiouracil, methimazole, cocaine/levamisole + DILE causes
2. IBD
3. Primary Sclerosing Cholangitis
4. Endocarditis
5. TB
6. SLE
Drug-induced lupus
1. hydralazine
2. D-penicillamine
3. minocycline (for acne)
4. procainamide
5. anti-TNF
6. isoniazid (and less rifampicin)
7. IFN
Hypereosinophilia
0. allergic / infectious / malignancy
1. EGPA
2. IBD
3. sarcoidosis
4. HIV infection
5. IgG4-RD
6. autoimmune lymphoproliferative syndrome
7. hyper-IgE syndrome (LoF of STAT3)
8. Kimura
9. Kussmaul
10. eosinophilia-myalgia (L-tryptophan supplement) / toxic oil syndrome (rapeseed oil)
11. early eosinophilic fasciitis
Lymphadenopathy Dx
, 0. Infections / malignancy / systemic inflammatory (SLE, Sjögren, sarcoidosis, IgG4-RD, Still, HIDS, Kawasaki)
1. Kikuchi (necrotic lymphadenopathy + fever)
2. Kimura (masses + lymphadenopathy + eosinophilia + ↑IgE)
3. Histiocytosis
i) Langerhans
ii) Rosai-Dorfman
4. ALPS
5. Castleman (clonal lymphoproliferative)
TMA + MAHA in systemic autoimmune diseases
1. cAPS
2. SLE
3. SSc
HCQ side effects
Retinopathy (attaches to pigmented retinal epithelium)
Skin: exacerbation of psoriasis, exfoliative dermatitis, pruritus, urticaria, skin photosensitivity, pustulosis
Myopathy
Cardiomyopathy
QT prolongation
Hemolysis (in G6PD deficiency)
Cytopenias
DRESS
Peripheral neuropathy
Nephropathy (including curvilinear inclusion bodies, like in Fabry)
Rheumatology emergencies
Alveolar hemorrhage
SRC
AION [GCA] (blindness)
Necrotizing scleritis [RA] (can lead to scleromalacia perforans) / PUK (can lead to corneal melt)
Anti-GBM
caPS
[…]
Dactylitis
Seronegative (PsA, Reactive)
Sarcoidosis
TB (“spina vendosa”)
Gout
Sickle cell anemia (only in children)
Keratitis
RA
GPA + vasculitides
Sjögren
Cogan (interstitial)
[…]
Scleritis
RA (10-18%)
↓ complement
1. SLE (low C3, C4)
2. Sjögren
3. cryoglobulinemia (types II & III, with RF) (low C3, C4)
4. HBV / HCV
5. HUVS (HBV and C1q autoantibodies)
6. Endocarditis (immune-complexes)
7. post-streptococcal GN (antigens activate alternative pathway, only ↓C3)
8. membranoproliferative GN (C3-DDD)
9. IgG4-RD (tubulointerstitial nephritis) (low C3)
DIP arthritis
1. seronegative
2. OA
3. multicentric reticulohistiocytosis (erosive)
4. gout (tophaceous)
5. PBC
p-ANCA
(other than AAV)
1. drug-induced: propylthiouracil, methimazole, cocaine/levamisole + DILE causes
2. IBD
3. Primary Sclerosing Cholangitis
4. Endocarditis
5. TB
6. SLE
Drug-induced lupus
1. hydralazine
2. D-penicillamine
3. minocycline (for acne)
4. procainamide
5. anti-TNF
6. isoniazid (and less rifampicin)
7. IFN
Hypereosinophilia
0. allergic / infectious / malignancy
1. EGPA
2. IBD
3. sarcoidosis
4. HIV infection
5. IgG4-RD
6. autoimmune lymphoproliferative syndrome
7. hyper-IgE syndrome (LoF of STAT3)
8. Kimura
9. Kussmaul
10. eosinophilia-myalgia (L-tryptophan supplement) / toxic oil syndrome (rapeseed oil)
11. early eosinophilic fasciitis
Lymphadenopathy Dx
, 0. Infections / malignancy / systemic inflammatory (SLE, Sjögren, sarcoidosis, IgG4-RD, Still, HIDS, Kawasaki)
1. Kikuchi (necrotic lymphadenopathy + fever)
2. Kimura (masses + lymphadenopathy + eosinophilia + ↑IgE)
3. Histiocytosis
i) Langerhans
ii) Rosai-Dorfman
4. ALPS
5. Castleman (clonal lymphoproliferative)
TMA + MAHA in systemic autoimmune diseases
1. cAPS
2. SLE
3. SSc
HCQ side effects
Retinopathy (attaches to pigmented retinal epithelium)
Skin: exacerbation of psoriasis, exfoliative dermatitis, pruritus, urticaria, skin photosensitivity, pustulosis
Myopathy
Cardiomyopathy
QT prolongation
Hemolysis (in G6PD deficiency)
Cytopenias
DRESS
Peripheral neuropathy
Nephropathy (including curvilinear inclusion bodies, like in Fabry)
Rheumatology emergencies
Alveolar hemorrhage
SRC
AION [GCA] (blindness)
Necrotizing scleritis [RA] (can lead to scleromalacia perforans) / PUK (can lead to corneal melt)
Anti-GBM
caPS
[…]
Dactylitis
Seronegative (PsA, Reactive)
Sarcoidosis
TB (“spina vendosa”)
Gout
Sickle cell anemia (only in children)
Keratitis
RA
GPA + vasculitides
Sjögren
Cogan (interstitial)
[…]
Scleritis
RA (10-18%)
