Systemic lupus erythematosus (SLE) and neonatal lupus

Fever, fatigue, weight loss, arthritis, malar or discoid rash, photosensitivity, nephritis, seizures or psychosis, pleurisy, ILD, pericarditis, anaemia, leukopenia, thrombocytopenia.
Investigations: CBC, ESR/CRP, ANA, anti-dsDNA, anti-Sm, antiphospholipid antibodies, anti-Ro/La/U1 RNP, urinalysis and creatinine, C3/C4, renal biopsy for nephritis, chest X-ray, echo, abdominal ultrasound.

Management

Sun protection (SPF 50 or more), education, vaccination (pneumococcal, influenza), monitor BP, renal, blood and cardiovascular risk.
All patients: S: hydroxychloroquine 200–400 mg once daily (5 mg/kg/day, maximum 400 mg).
Mild musculoskeletal pain or serositis: NSAIDs (e.g. diclofenac 50 mg 2–3 times daily, meloxicam 7.5–15 mg daily).

Steroid dose	Regimen	Use
Low	A: Prednisolone up to 7.5 mg/day	Mild disease (skin, joints)
Moderate	A: Prednisolone 10–30 mg/day	Serositis, cytopenia
High / pulse	A: Prednisolone 1–2 mg/kg/day; D: methylprednisolone 500–1000 mg/day for 3 days	Nephritis, CNS lupus, severe cytopenias, myocarditis, alveolar haemorrhage

Indication	Immunosuppressant
Moderate disease; lupus nephritis maintenance	S: Azathioprine 1–2 mg/kg/day
Arthritis, skin disease	S: Methotrexate 15–25 mg/week
Lupus nephritis III/IV/V, pneumonitis, vasculitic ulcers, cytopenias	S: Mycophenolate mofetil – induction 2–3 g/day, maintenance 1–2 g/day
Severe organ involvement (renal, CNS, cardiac)	S: Cyclophosphamide 500–1000 mg/m² monthly × 6, then MMF or azathioprine
Refractory or severe	S: Rituximab IV 1000 mg × 2 doses, 2 weeks apart

Adjuncts: low-dose aspirin with antiphospholipid antibodies; ACE inhibitor/ARB for proteinuria; statins; calcium/vitamin D and bisphosphonate on long-term steroids; co-trimoxazole PJP prophylaxis on high-dose steroids or cyclophosphamide.

From maternal anti-Ro/SSA, anti-La/SSB (or anti-U1 RNP) antibodies; mother may have SLE or Sjögren's or be asymptomatic.
Annular/periorbital rash (resolves by 6–8 months), photosensitivity, congenital heart block (often permanent), hepatitis, cytopenias. Check ECG, CBC, LFTs, anti-Ro/La.
Sun protection and mild topical steroid for rash; pacemaker for severe heart block; in later pregnancies hydroxychloroquine and fetal echocardiography at 16–26 weeks.