Master Arjun, a 7-year-old male child, 1st order child born of a non-consanguineous marriage from Varanasi, Uttar Pradesh, presented with complaints of an acute, non-itchy red-purple raised rash over both lower legs and buttocks for 5 days, severe colicky periumbilical abdominal pain with two episodes of blood-stained loose stools for 3 days, and swelling and pain in both ankles for 4 days, preceded by a sore throat and low-grade fever 2 weeks ago.

HOPI

The history is dated back to 2 weeks ago when the child had an episode of upper respiratory tract infection (sore throat, rhinorrhea, low fever) which subsided with symptomatic antipyretics.

• Cutaneous Rash (Palpable Purpura):
  • Appeared 5 days ago, initially around both ankles and shins, spreading upwards to thighs and buttocks.
  • Completely spared the trunk, chest, neck, and face.
  • Lesions began as erythematous macules/urticarial wheals which transformed into raised, dark purple, palpable nodules and petechiae measuring 2 to 8 mm.
  • Completely non-pruritic, non-tender, and do not fade on pressure Points to leukocytoclastic vasculitis with erythrocyte extravasation into the dermis.
• Severe Colicky Abdominal Pain & GI Bleeding:
  • Developed 3 days ago; severe, episodic, cramping periumbilical pain causing the child to curl into a fetal position.
  • Followed by 2 episodes of passing loose stools mixed with dark red blood and mucus Reflects mucosal and submucosal ischemia, hemorrhage, and bowel wall edema.
  • Mother noted no bilious vomiting or visible abdominal lump.
• Joint Symptoms (Arthritis/Arthralgia):
  • Noticed 4 days ago; acute, painful swelling around both ankles, accompanied by refusal to walk or bear weight.
  • Periarticular swelling; skin overlying ankles was puffy but not warm or red.
• Urinary Symptoms (Renal Involvement):
  • Mother noticed the urine appeared slightly smoky and dark over the last 2 days. No burning micturition, no gravel.
• Negative History:
  • No history of epistaxis, bleeding from gums, or unprovoked hematomas Rules out Immune Thrombocytopenia (ITP) and bleeding disorders.
  • No history of high-grade unyielding fever or strawberry tongue Rules out Kawasaki Disease.
  • No history of malar rash, oral ulcers, or photosensitivity Rules out Systemic Lupus Erythematosus.
  • No history of sudden, agonizing scrotal pain or testicular swelling Rules out scrotal vasculitis or acute testicular torsion.

Past History

• No prior history of similar purpuric skin rashes, bloody diarrhea, or renal disease.
• Had mild bronchial asthma treated with inhaled salbutamol as needed.

Family history

• Non-consanguineous marriage.
• Father 38 years, school teacher; Mother 35 years, homemaker; both healthy.
• Elder sister (10 years old) has atopic dermatitis and allergic rhinitis.

Immunization history

• Fully immunized up to age according to the National Immunization Schedule.

Dietary history

• Consumes a standard mixed home diet meeting 100% of ICMR-NIN RDA for age.

24-Hour Recall Deficit Analysis

$$ \text{Ideal Body Weight (IBW for 7 years, 50th centile WHO)} = 23.0\text{ kg} $$

Nutrient	Expected Intake (ICMR-NIN 2024 for IBW 23 kg)	Observed Intake	Deficit	Percentage Deficit
Energy (kcal)	$23.0\text{ kg} \times 65\text{ kcal/kg} = 1495\text{ kcal}$	1020 kcal	475 kcal	31.8% Deficit
Protein (g)	$23.0\text{ kg} \times 0.98\text{ g/kg} = 22.5\text{ g}$	16.2 g	6.3 g	28.0% Deficit

Socioeconomic and KAP

• Modified BG Prasad Socioeconomic Class II (Upper Middle Class).
• Parents panicked by the appearance of "blood spots" and bloody stools; seeking urgent hospital care.

Summary of History

Master Arjun, a 7-year-old male child, presents with a 5-day history of post-infectious palpable purpura over gravity-dependent lower limbs and buttocks, acute colicky abdominal pain with bloody stools, bilateral ankle periarticular arthritis, and smoky urine, in the absence of mucosal bleeding or thrombocytopenia.

I would like to consider a provisional diagnosis of IgA Vasculitis (Henoch-Schönlein Purpura) presenting with the classical tetrad of palpable purpura, arthritis, gastrointestinal vasculitis, and active HSP nephritis.

General head to toe examination

• Behavioral State: Prechtl State 3 (alert, cooperative, curling up occasionally during bouts of abdominal colic).
• Vitals:
  • Heart Rate: 98 beats/minute, regular, good volume.
  • Respiratory Rate: 20 breaths/minute, regular.
  • Blood Pressure: $112/74\text{ mmHg}$ ($90^{\text{th}}\text{ to } 95^{\text{th}}$ centile $\rightarrow$ Pre-hypertensive / Early Hypertension secondary to active glomerulonephritis).
  • Temperature: $37.0^\circ\text{C}$ (afebrile).
  • Capillary Refill Time: $<2$ seconds.
• Anthropometry:

Parameter	Observed	Expected (50th WHO)	Centile	Inference
Weight	22.8 kg	23.0 kg	$50^{\text{th}}\text{ centile}$	Normal nutrition
Height	122.0 cm	122.0 cm	$50^{\text{th}}\text{ centile}$	Normal Stature
BMI	$15.3\text{ kg/m}^2$	$15.5\text{ kg/m}^2$	$50^{\text{th}}\text{ centile}$	Normal

• Comprehensive Dermatological Examination:
  • Palpable Purpura: Extensive, raised, non-blanching, discrete and confluent purpuric macules and plaques measuring 2 to 10 mm.
  • Anatomical Distribution: Strictly symmetrical, concentrated over the extensor surfaces of the lower extremities (dorsum of feet, malleoli, pretibial area, knees) and buttocks.
  • Spared Areas: Complete absence of lesions on the trunk, palms, soles, neck, and face.
  • Edema: Mild non-pitting periarticular subcutaneous edema overlying the dorsum of both feet and ankles.

Musculoskeletal Examination

• Ankles (Bilateral): Tender periarticular soft tissue swelling; active and passive dorsiflexion eliciting pain; no true intra-articular effusion (absence of fluid fluctuation); no erythema.
• Knees & Wrists: Full range of motion, non-tender.

Systemic Examination

Abdomen

• Symmetrically flat, moves with respiration.
• Palpation: Soft, generalized mild tenderness, maximal in the periumbilical region; no localized right iliac fossa tenderness, no muscular rigidity, no rebound tenderness; no palpable sausage-shaped abdominal mass (rules out ileocolic intussusception).
• Organomegaly: Liver palpable 1.0 cm below costal margin, soft; spleen not palpable.
• Auscultation: Hyperactive bowel sounds (6-8/minute).
• Digital Rectal Examination: Stool on glove is brown, streaked with dark red blood; stool occult blood test positive.

Cardiovascular, Respiratory & Genitourinary Systems

• CVS & RS: Clinically normal.
• Genitalia: Scrotum normal, non-swollen, non-tender; testes palpable bilaterally, normal volume, non-tender (excludes acute scrotal vasculitis).

Summary

Master Arjun, a 7-year-old male child, presents with the classic clinical tetrad of IgA Vasculitis fulfilling the EULAR/PRINTO/PRES consensus criteria: mandatory non-thrombocytopenic palpable purpura on lower limbs and buttocks, colicky abdominal pain with hematochezia, bilateral ankle periarticular arthritis, and elevated blood pressure ($112/74\text{ mmHg}$) with smoky urine indicating active glomerulonephritis.

Final Clinical Diagnosis: IgA Vasculitis (Henoch-Schönlein Purpura), presenting with acute gastrointestinal vasculitis and active HSP Nephritis (microscopic hematuria, proteinuria, pre-hypertension), without intussusception or acute kidney injury.

Differential Diagnosis

Disorder	Points IN FAVOR	Points AGAINST
IgA Vasculitis (HSP)	Palpable purpura (shins/buttocks), normal platelets, colicky abdominal pain, ankle arthritis, hematuria	Primary Clinical Diagnosis
Immune Thrombocytopenia (ITP)	Purpuric skin lesions, male child	ITP purpura is flat/macular (not palpable), randomly distributed over trunk and face; platelet count is severely reduced ($<20,000/\mu\text{L}$); lacks arthritis, abdominal pain, or nephritis
Acute Glomerulonephritis (PSGN)	Post-pharyngitic onset, hematuria, hypertension	PSGN lacks palpable purpuric rash, colicky abdominal pain, hematochezia, or arthritis; complement C3 is low in PSGN (normal in HSP)
Meningococcemia	Acute purpuric rash, fever, lethargy	Child is afebrile, non-toxic; meningococcemia features rapid progression to fulminant shock, DIC, purpura fulminans, and high fever
Acute Appendicitis / Intussusception	Severe colicky abdominal pain, vomiting, bloody stools	Does not account for symmetrical lower limb palpable purpura or ankle arthritis; purpura precedes or accompanies abdominal signs

Investigation Protocol & Diagnostic Workup

flowchart TD
    A["Child with Palpable Purpura, Abdominal Pain & Arthritis"] --> B["Stat CBC, Platelet Count & Coagulation Profile (PT/INR/aPTT)"]
    B --> C{"Platelets Normal or Elevated (> 150,000) & Coagulation Normal?"}
    C -->|Yes| D["Confirm Non-Thrombocytopenic Purpura (IgA Vasculitis)"]
    D --> E["Stat Urinalysis & Spot UPCR: Screen for HSP Nephritis"]
    E --> F{"Hematuria > 5 RBCs/HPF OR Proteinuria UPCR > 0.5?"}
    F -->|Yes| G["Stage HSP Nephritis: RFT, Blood Pressure, 24-hr Urine Protein"]
    F -->|No| H["Serial Weekly Urinalysis & BP Surveillance for 6 Months"]
    G --> I{"Nephrotic Proteinuria (UPCR > 2) OR Elevated Creatinine?"}
    I -->|Yes| J["Indication for Renal Biopsy (ISKDC Staging) & Corticosteroids"]

1. Hematology & Coagulation

• Platelet Count: $380,000/\mu\text{L}$ (Completely normal / reactive; definitively confirms non-thrombocytopenic purpura).
• Hemoglobin: $11.8\text{ g/dL}$; TLC: $11,200/\mu\text{L}$ ($68\%$ neutrophils).
• Coagulation Profile: Prothrombin Time (PT) $12.4\text{ sec}$, INR $1.02$, aPTT $28.0\text{ sec}$ (Normal; rules out bleeding diathesis).

2. Urinalysis & Renal Function Tests (HSP Nephritis Staging)

• Urine Routine & Microscopy:
  • Protein: $2+$ on dipstick ($100\text{ mg/dL}$).
  • Red Blood Cells: $25-30\text{ RBCs/HPF}$ (Dysmorphic erythrocytes with red cell casts $\rightarrow$ confirms glomerular hematuria).
  • Absence of glycosuria, nitrites, or pus cells.
• Spot Urine Protein-to-Creatinine Ratio (UPCR): $1.1\text{ mg/mg}$ (Significant non-nephrotic proteinuria; normal $<0.2\text{ mg/mg}$).
• Renal Function Tests: Serum Creatinine $0.48\text{ mg/dL}$ (Normal for 7y), BUN $14\text{ mg/dL}$, Serum Albumin $3.6\text{ g/dL}$, Serum Electrolytes normal.
• Serum Complement C3 and C4: Normal (C3 $112\text{ mg/dL}$, C4 $28\text{ mg/dL}$; rules out PSGN and Lupus).

3. Abdominal Imaging

• High-Resolution Abdominal Ultrasonography:
  • Prominent bowel wall thickening ($4.5\text{ mm}$) with submucosal edema in the terminal ileum and cecum.
  • No target or donut sign (definitively excludes ileo-ileal or ileocolic intussusception).
  • Kidneys bilaterally normal in size and echogenicity.

Therapeutic Management Protocol

1. Management of Gastrointestinal & Articular Manifestations

1. Short-Course Corticosteroids (For Severe Abdominal Pain & Arthritis):
   • Oral Prednisolone: $1.0\text{ to } 2.0\text{ mg/kg/day}$ ($25-30\text{ mg/day}$) orally for 1 to 2 weeks, followed by a rapid taper over 2 weeks.
   • Clinical Evidence: Steroids dramatically reduce intestinal submucosal edema, relieve severe colicky pain, resolve GI bleeding, and accelerate joint recovery.
   • Viva Trap Warning: Corticosteroids do NOT prevent the development or progression of HSP nephritis! Prophylactic steroids should never be given to prevent kidney disease.
2. Analgesia: Acetaminophen (Paracetamol $15\text{ mg/kg/dose}$) as needed. (Avoid NSAIDs due to active GI mucosal bleeding and concurrent glomerulonephritis).

2. Management of HSP Nephritis

1. Renoprotection & Blood Pressure Control:
   • Initiate oral ACE Inhibitor (Enalapril at $0.1-0.2\text{ mg/kg/day}$) to reduce glomerular hyperfiltration, control pre-hypertension, and suppress proteinuria.
2. Long-Term Monitoring Protocol (Mandatory 6-Month Rule):
   • Urine dipstick and blood pressure checks weekly for Month 1, every 2 weeks for Months 2 and 3, and monthly up to 6 months.
   • If proteinuria resolves and urinalysis is clear at 6 months, long-term renal prognosis is excellent.