Miss Ananya, a 13-year-old female adolescent, 1st order child born of a non-consanguineous marriage from Kolkata, West Bengal, presented with complaints of low-to-moderate grade intermittent fever for 6 weeks, an erythematous butterfly rash over both cheeks and the bridge of the nose for 4 weeks, diffuse thinning and falling of hair for 4 weeks, pain and swelling of both wrists and small joints of the hands for 3 weeks, painless mouth sores for 2 weeks, and progressive puffiness around the eyes with swelling of both feet for 10 days.

HOPI

The history is dated back to 6 weeks ago when the adolescent began developing unexplained low-to-moderate grade intermittent fever accompanied by overwhelming fatigue and malaise.

• Malar (Butterfly) Rash & Photosensitivity:
  • Appeared 4 weeks ago over both cheeks, extending continuously across the bridge of the nose.
  • Characteristically spares the nasolabial folds Classic physical distinction from dermatomyositis, rosacea, and seborrheic dermatitis which involve the nasolabial folds.
  • Mother noted marked erythema, burning, and worsening of the rash after outdoor sports in sunlight (photosensitivity).
• Diffuse Alopecia & Oral Ulcerations:
  • Experienced progressive, non-scarring diffuse loss of scalp hair; clumps of hair collected on pillows and brushes; short broken hairs along frontal hairline.
  • Noticed 2 to 3 painless ulcers on the roof of the mouth (hard palate) 2 weeks ago; discovered incidentally during dental hygiene Painless character is highly specific for autoimmune lupus ulcers compared to painful viral aphthae.
• Polyarthritis:
  • Symmetrical pain, morning stiffness ($>45$ minutes), and swelling involving bilateral wrists, metacarpophalangeal (MCP) joints, and proximal interphalangeal (PIP) joints for 3 weeks.
• Renal Manifestations (Lupus Nephritis):
  • For the past 10 days, mother noticed matutinal puffiness around both eyes on waking, accompanied by swelling of both feet and ankles.
  • Urine appeared dark, concentrated, and characteristically frothy and bubbly Direct visual marker of heavy glomerular proteinuria.
• Negative History:
  • No history of severe unremitting headache, seizures, confusion, hallucinations, or sudden behavioral change Rules out acute Neuropsychiatric SLE (NPSLE).
  • No history of sharp pleuritic chest pain aggravated by lying supine or relieved by sitting forward Rules out acute lupus pericarditis or pleuritis.
  • No history of spontaneous epistaxis, bleeding gums, or purpura Rules out severe autoimmune thrombocytopenia or secondary Evans syndrome.
  • No history of painful cold-induced blue-white discoloration of fingers (Raynaud phenomenon).

Past History

• No prior history of autoimmune disease, chronic joint swelling, or hospitalizations.
• No history of antiepileptic drug intake (carbamazepine, phenytoin) or hydralazine (rules out drug-induced lupus).

Family history

• Born of a non-consanguineous marriage.
• Father 44 years, healthy; Mother 40 years, diagnosed with Hashimoto Thyroiditis, taking Levothyroxine.
• Maternal Grandmother: Had Systemic Lupus Erythematosus complicated by Lupus Nephritis, died at 58 years of age.
• Pedigree confirms a strong familial predisposition to multigenerational systemic autoimmunity.

Immunization history

• Fully immunized up to age as per the National Immunization Schedule, including MMR, typhoid, and HPV vaccination.

Dietary history

• Consumes a balanced home diet meeting nutritional requirements.

24-Hour Recall Deficit Analysis

$$ \text{Ideal Body Weight (IBW for 13 years, 50th centile WHO)} = 45.0\text{ kg} $$

Nutrient	Expected Intake (ICMR-NIN 2024 for IBW 45 kg)	Observed Intake	Deficit	Percentage Deficit
Energy (kcal)	$45.0\text{ kg} \times 48\text{ kcal/kg} = 2160\text{ kcal}$	1580 kcal	580 kcal	26.8% Deficit
Protein (g)	$45.0\text{ kg} \times 0.95\text{ g/kg} = 42.8\text{ g}$	32.0 g	10.8 g	25.2% Deficit

Socioeconomic and KAP

• Modified BG Prasad Socioeconomic Class I (Upper Class).
• Both parents are college graduates; highly motivated and aware of familial lupus risk.

Summary of History

Miss Ananya, a 13-year-old adolescent female with a maternal family history of SLE, presented with a 6-week history of fever, malar rash sparing nasolabial folds, photosensitivity, non-scarring alopecia, painless oral ulcers, symmetrical small joint polyarthritis, and nephrotic-range edema with frothy urine, in the absence of neuropsychiatric or serositis signs.

I would like to consider a provisional diagnosis of Pediatric Systemic Lupus Erythematosus (pSLE), presenting with active multi-system involvement including mucocutaneous, musculoskeletal, and Lupus Nephritis.

General head to toe examination

• Behavioral State: Calm, cooperative, fully oriented.
• Vitals:
  • Heart Rate: 92 beats/minute, regular, normal volume.
  • Respiratory Rate: 18 breaths/minute, regular.
  • Blood Pressure: $134/88\text{ mmHg}$ ($>95^{\text{th}}$ centile $\rightarrow$ Stage 1 Hypertension secondary to active lupus nephritis).
  • Temperature: $37.2^\circ\text{C}$ (Low-grade pyrexia).
  • Capillary Refill Time: $<2$ seconds.
• Anthropometry:

Parameter	Observed	Expected (50th WHO)	Centile	Inference
Weight	46.5 kg (with edema)	45.0 kg	$50^{\text{th}}\text{ centile}$	Fluid retention ~1.5 kg
Height	156.0 cm	156.0 cm	$50^{\text{th}}\text{ centile}$	Normal Stature
BMI	$19.1\text{ kg/m}^2$	$18.5\text{ kg/m}^2$	$50^{\text{th}}\text{ centile}$	Normal

• Comprehensive Dermatological & Mucosal Examination:
  • Malar Rash: Fixed, confluent, erythematous, slightly raised macular eruption over bilateral malar eminences and across the nasal bridge; nasolabial folds are completely spared.
  • Hair: Diffuse non-scarring alopecia; hair pull test positive ($>10$ hairs per tug); fine, fractured, frizzy hairs visible along the frontal hairline (Lupus hairs).
  • Oral Cavity: Two discrete, shallow, painless, erythematous mucosal ulcers with white necrotic bases on the hard palate.
  • Edema: Bilateral soft pitting pedal edema extending up to mid-shin level ($2+$); mild bilateral periorbital puffiness.
  • Pallor: Mild pallor in palpebral conjunctiva.

Musculoskeletal Examination

• Symmetrical tenderness and mild boggy synovial swelling involving bilateral wrists, 2nd and 3rd MCP joints, and PIP joints; active finger flexion restricted by $10^\circ$; no fixed joint deformities or swan-neck subluxations (non-erosive synovitis).

Systemic Examination

Cardiovascular & Respiratory Systems

• Normal heart sounds ($S_1, S_2$ normal), no murmurs, no pericardial rub; chest clear with normal vesicular breath sounds bilaterally (no pleural effusion).

Abdomen

• Soft, non-tender; liver palpable 1.5 cm below costal margin, non-tender; spleen not palpable; no ascites.

Central Nervous System

• Alert, oriented to time, place, and person; cranial nerves I-XII intact; normal motor and sensory exams; fundoscopy normal (no cotton-wool cytoid bodies or retinal hemorrhages).

Summary

Miss Ananya, a 13-year-old female adolescent with familial autoimmune background, presents with constitutional symptoms (fever, weight loss), fixed malar rash sparing nasolabial folds, photosensitivity, non-scarring alopecia, painless palatal ulcers, symmetrical non-erosive polyarthritis, and nephrotic-nephritic features (Stage 1 hypertension $134/88\text{ mmHg}$, periorbital and pedal edema, frothy urine).

Final Clinical Diagnosis: Pediatric Systemic Lupus Erythematosus (pSLE) fulfilling EULAR/ACR 2019 criteria (Score $>25$ points), complicated by active Lupus Nephritis (likely Class III or IV Diffuse Proliferative), without neuropsychiatric SLE or serositis.

Differential Diagnosis

Condition	Points IN FAVOR	Points AGAINST
Pediatric SLE	Malar rash, photosensitivity, alopecia, oral ulcers, polyarthritis, hypertension, edema, positive family history	Primary Clinical Diagnosis
Juvenile Dermatomyositis (JDM)	Facial rash, photosensitivity, arthritis	JDM rash is Heliotrope (violaceous eyelid edema) with Gottron papules over knuckles; features profound symmetrical proximal muscle weakness (Gowers sign); lacks nephritis or oral ulcers
Systemic JIA (sJIA)	Fever, polyarthritis, rash, lymphadenopathy	Rash in sJIA is evanescent salmon-pink (not fixed malar); fever is spiking quotidian; sJIA lacks alopecia, oral ulcers, or nephritis
Mixed Connective Tissue Disease (MCTD)	Polyarthritis, puffiness, ANA positivity	MCTD is defined by high-titer anti-U1-RNP antibodies, prominent Raynaud phenomenon, and sclerodactyly; lacks typical malar rash
Post-Streptococcal Glomerulonephritis (PSGN)	Edema, hypertension, dark urine	PSGN does not account for malar butterfly rash, alopecia, oral ulcers, or polyarthritis; resolves within 6-8 weeks

Investigation Protocol & Diagnostic Workup

flowchart TD
    A["Adolescent Female with Malar Rash, Polyarthritis & Proteinuria"] --> B["Stat Indirect Immunofluorescence ANA on HEp-2 Cells"]
    B --> C{"ANA Positive (Titer ≥ 1:80)?"}
    C -->|No| D["SLE Excluded (Consider Other Connective Tissue Disorders)"]
    C -->|Yes| E["Profile: Anti-dsDNA, Anti-Sm, Anti-Ro/La, aPL & Complement C3/C4"]
    E --> F["Renal Workup: Urinalysis, Spot UPCR, 24-hr Protein, Serum Creatinine"]
    F --> G{"Proteinuria UPCR ≥ 0.5 mg/mg OR Active RBC Casts?"}
    G -->|Yes| H["MANDATORY Ultrasound-Guided Percutaneous Renal Biopsy"]
    H --> I["ISN/RPS Histological Staging (Class I to VI)"]
    I --> J["Class III / IV Proliferative LN: Pulse Methylprednisolone + MMF / Cyclophosphamide"]

1. Autoimmune Serological Profile (The Confirmatory Panel)

• Antinuclear Antibodies (ANA): Strongly positive ($1:1280$ titer, homogeneous and speckled pattern on HEp-2 cells).
• Anti-Double Stranded DNA (anti-dsDNA): Strongly positive ($> 400\text{ IU/mL}$, normal $<20\text{ IU/mL}$) $\rightarrow$ correlates directly with active lupus nephritis.
• Anti-Smith (anti-Sm) Antibodies: Positive (confirms high-specificity SLE diagnosis).
• Serum Complement:
  • Complement C3: $42\text{ mg/dL}$ (Severely consumed; normal $90-180\text{ mg/dL}$).
  • Complement C4: $6.5\text{ mg/dL}$ (Severely depressed; normal $15-45\text{ mg/dL}$).
  • Inference: Profound classical complement consumption by circulating immune complexes.
• Anti-Phospholipid Antibodies: Lupus Anticoagulant negative, Anti-cardiolipin IgG/IgM negative.

2. Renal & Hematological Panel

• Complete Blood Count:
  • Hemoglobin: $10.2\text{ g/dL}$ (Mild normocytic anemia).
  • Total Leukocyte Count: $3400/\mu\text{L}$ (Leukopenia; normal $4500-11,000/\mu\text{L}$).
  • Platelet Count: $165,000/\mu\text{L}$.
• Urinalysis:
  • Protein: $3+$ ($300\text{ mg/dL}$).
  • Microscopy: $15-20\text{ dysmorphic RBCs/HPF}$, granular and red cell casts present.
• Spot Urine Protein-to-Creatinine Ratio (UPCR): $2.4\text{ mg/mg}$ (Nephrotic-range proteinuria; normal $<0.2\text{ mg/mg}$).
• Renal Function: Serum Creatinine $0.72\text{ mg/dL}$ (mildly elevated for age), BUN $22\text{ mg/dL}$, Serum Albumin $2.6\text{ g/dL}$ (Hypoalbuminemia).

3. Histopathological Renal Biopsy (ISN/RPS Classification)

• Indication: Proteinuria $>0.5\text{ g/24 hr}$ with active urinary sediment and hypertension.
• Renal Biopsy Findings:
  • Light Microscopy: Endocapillary and extracapillary cellular crescents in $65\%$ of glomeruli with subendothelial "wire-loop" deposits.
  • Immunofluorescence: "Full-House" immune deposition (intense granular deposition of IgG, IgA, IgM, C3, and C1q along capillary walls and mesangium).
  • Histological Diagnosis: ISN/RPS Class IV-G (A) Diffuse Proliferative Lupus Nephritis (Active).

Therapeutic Management Protocol (EULAR/ACR 2019 / KDIGO 2021)

1. Induction Immunosuppression for Class IV Lupus Nephritis (Months 1 to 6)

1. Intravenous Corticosteroid Pulses:
   • IV Methylprednisolone: $30\text{ mg/kg/day}$ (max $1000\text{ mg/day}$) infused over 2 hours for 3 consecutive days, followed by oral Prednisolone at $1.0\text{ mg/kg/day}$ ($45\text{ mg/day}$) tapered gradually over 3 to 6 months.
2. First-Line Immunosuppressive Agent (Choose MMF or Cyclophosphamide):
   • Oral Mycophenolate Mofetil (MMF): $1200\text{ mg/m}^2/\text{day}$ divided BID ($750\text{ mg}$ BID; preferred in adolescents to preserve fertility and avoid gonadal toxicity).
   • Alternative: IV Cyclophosphamide (Euro-Lupus regimen: $500\text{ mg}$ fixed dose IV every 2 weeks $\times 6$ doses).

2. Universal Background & Supportive Therapy

1. Hydroxychloroquine (HCQ):
   • $5.0\text{ mg/kg/day}$ orally (max $400\text{ mg/day}$; $200\text{ mg}$ once daily) mandatory for ALL SLE patients for life; prevents flares and protects renal function.
2. Renoprotection & Antihypertensive:
   • Oral Enalapril at $0.1-0.2\text{ mg/kg/day}$ to achieve target blood pressure $<90^{\text{th}}$ centile and reduce proteinuria.
3. Photoprotection: Broad-spectrum high-SPF sunscreen ($\ge 50$) applied 30 minutes before sun exposure; protective clothing.
4. Bone Protection: Calcium ($1000\text{ mg/day}$) and Vitamin D3 ($1000\text{ IU/day}$) co-administered during steroid therapy.