Petechiae are non-blanching, pinpoint haemorrhages caused by rupture of small dermal blood vessels. They are never normal in children and always warrant careful assessment. 🔴 Pathophysiology: Can result from platelet abnormalities (low number or dysfunction), coagulation defects, vascular fragility, or infection-induced endothelial damage. ⚠️ In children, meningococcal sepsis must always be excluded urgently.

🩺 Initial Assessment

History:
- ⏱️ Onset & duration – acute vs chronic rash.
- 🤒 Associated symptoms: fever, malaise, joint pain, abdominal pain, bleeding elsewhere.
- 🧬 Medical/family history: bleeding disorders, autoimmune disease.
- 💊 Medications: NSAIDs, aspirin, antibiotics, anticoagulants.
- 🥗 Diet & lifestyle: vitamin C deficiency, recent trauma, exertion.
Examination:
- 👀 General: pallor, jaundice, irritability, systemic illness.
- 🌡️ Vitals: fever, tachycardia, hypotension (shock).
- 🖐️ Skin: distribution, blanching vs non-blanching, bruises/ecchymoses.
- 🩸 Abdominal: hepatosplenomegaly (malignancy, infection, portal HTN).
- 🦵 Joints: swelling, tenderness (vasculitis, HSP).
- ENT: pharyngitis, lymphadenopathy, tonsillar exudate.

🔬 Investigations

🧪 Bloods: CBC (platelets, Hb, WCC), coagulation profile, CRP/ESR, LFTs, U&E.
🦠 Microbiology: Blood cultures if sepsis, throat swab if streptococcal infection, viral serology (EBV, CMV).
🦴 Bone marrow aspiration: if unexplained cytopenias or suspected leukaemia/aplastic anaemia.
🥗 Other: Vitamin levels (C, B12, folate), autoimmune screen (ANA, ANCA).

🚑 Management Principles

Immediate Stabilisation:
- 💉 ABC approach (airway, breathing, circulation).
- ⚡ Broad-spectrum antibiotics if meningococcal sepsis suspected (do not delay).
- Oxygen, IV fluids if shocked.
Treat Underlying Cause:
- 🦠 Infections → antibiotics/antivirals as indicated.
- 🩸 ITP → IVIG or steroids if severe bleeding.
- 🧬 Autoimmune vasculitis → steroids/immunosuppressants.
- 🔄 Nutritional → vitamin replacement (e.g. vitamin C for scurvy).
Supportive Care: Analgesia, antipyretics, transfusions if required.
Referral: Early haematology / infectious disease / rheumatology involvement.

💡 Red Flag: Petechial or purpuric rash with fever and shock = meningococcal sepsis until proven otherwise ➝ urgent antibiotics & resuscitation.

📊 Causes of Petechial Rash – Children vs Adults

Cause	Children 👶	Adults 👨‍⚕️
Viral Infections 🦠	Respiratory viruses (adenovirus, enterovirus), EBV, CMV, dengue	EBV, CMV, dengue, HIV
Bacterial Infections 🧫	Meningococcal septicaemia, scarlet fever, RMSF, endocarditis	Meningococcal sepsis, endocarditis, sepsis, RMSF
Platelet Disorders 🩸	ITP, leukaemia, congenital platelet defects	ITP, leukaemia, chemo-induced marrow suppression
Clotting Disorders 🧬	DIC, rare inherited disorders (e.g. haemophilia)	DIC, liver disease-related coagulopathy
Trauma/Mechanical 💥	NAI (child abuse), severe coughing/vomiting	Severe coughing, vomiting, weightlifting
Vasculitis 🔥	HSP, Kawasaki disease	SLE, PAN, systemic vasculitis
Medications 💊	Aspirin, NSAIDs, chemo agents	Aspirin, NSAIDs, anticoagulants, chemo
Nutritional 🥦	Vitamin C deficiency (scurvy)	Vitamin C deficiency, alcohol-related malnutrition

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Petechial Rash in Adult or Child

🩺 Initial Assessment

🔬 Investigations

🚑 Management Principles

📊 Causes of Petechial Rash – Children vs Adults

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