A 2-year-old girl from coastal Tamil Nadu presents with her father reporting recurrent respiratory infections, poor wound healing, and bleeding gums for the past 2 months. On examination, she is irritable, has petechiae on the lower extremities, swollen and bleeding gums, and corkscrew hairs on the extensor surfaces of the arms. Her mother mentions the child refuses to eat fruits and vegetables, preferring only rice and dal. Hemoglobin is 9.5 g/dL (microcytic). What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Vitamin C Deficiency (Scurvy) in a Young Child ### Key Clinical Features Pointing to Scurvy **Key Point:** The triad of bleeding gums, petechiae, and corkscrew hairs in a child with poor fruit/vegetable intake is pathognomonic for vitamin C deficiency (scurvy). ### Pathophysiology of Vitamin C Deficiency Vitamin C (ascorbic acid) is essential for: 1. **Collagen synthesis** — hydroxylation of proline and lysine residues (requires vitamin C as a cofactor for prolyl hydroxylase) 2. **Iron absorption** — reduces Fe³⁺ to Fe²⁺ for intestinal absorption 3. **Immune function** — antioxidant, supports neutrophil and lymphocyte function 4. **Wound healing** — collagen cross-linking Deficiency develops within 1–3 months of inadequate intake (fruits, vegetables, citrus). ### Clinical Manifestations of Scurvy ```mermaid flowchart TD A[Vitamin C Deficiency]:::outcome --> B[Defective Collagen Synthesis] B --> C1[Bleeding Gums<br/>Petechiae/Ecchymoses] B --> C2[Poor Wound Healing] B --> C3[Corkscrew Hairs<br/>Follicular Hyperkeratosis] B --> C4[Bone & Cartilage<br/>Defects] A --> D[Impaired Iron Absorption] D --> E[Microcytic Anemia] A --> F[Immune Dysfunction] F --> G[Recurrent Infections] style A fill:#e1f5ff style C1 fill:#fff3e0 style C2 fill:#fff3e0 style C3 fill:#fff3e0 style E fill:#fff3e0 style G fill:#fff3e0 ``` ### Specific Clinical Signs in This Case | Sign | Mechanism | Significance | |------|-----------|-------------| | **Bleeding gums** | Defective collagen in gingival tissue; capillary fragility | Hallmark of scurvy; may progress to tooth loss | | **Petechiae & ecchymoses** | Fragile blood vessels (defective Type IV collagen); bleeding tendency | Especially on lower extremities (pressure areas) | | **Corkscrew hairs** | Follicular hyperkeratosis; hair curls into spiral shape | Pathognomonic; seen on extensor surfaces | | **Poor wound healing** | Defective collagen deposition and cross-linking | Leads to delayed healing, infection risk | | **Recurrent infections** | Impaired neutrophil and lymphocyte function; defective collagen barriers | Vitamin C is cofactor for immune enzymes | | **Microcytic anemia** | Impaired iron absorption (Fe³⁺ not reduced to Fe²⁺) | Secondary to vitamin C deficiency | ### Dietary History: The Clue **High-Yield:** The child "refuses to eat fruits and vegetables, preferring only rice and dal" = no vitamin C sources. Rice and dal are devoid of vitamin C. Vitamin C is found in: - Citrus fruits (orange, lemon, lime) - Tomatoes - Leafy greens (spinach, kale) - Guava, papaya, mango - Potatoes (with skin) ### Laboratory Findings 1. **Serum vitamin C** — <0.2 mg/dL (normal >0.6 mg/dL) 2. **Hemoglobin** — 9.5 g/dL (anemia present) 3. **MCV** — Low (microcytic) due to impaired iron absorption 4. **Bleeding time** — May be prolonged (platelet dysfunction) 5. **Prothrombin time** — Normal (vitamin K-dependent factors intact) ### Management 1. **Immediate:** Vitamin C supplementation 100–200 mg daily (oral) 2. **Dietary:** Introduce fruits and vegetables rich in vitamin C 3. **Iron supplementation:** If anemia persists (vitamin C aids iron absorption) 4. **Monitor:** Gum bleeding resolves within 1–2 weeks; petechiae within 2–3 weeks 5. **Prevention:** Educate on balanced diet including fresh fruits/vegetables --- ## Differential Diagnosis: Why Other Vitamins Are Wrong | Feature | Vitamin C | Vitamin A | Vitamin K | Vitamin B6 | |---------|-----------|-----------|-----------|----------| | Bleeding gums | **Yes** (collagen defect) | No | No | No | | Petechiae/ecchymoses | **Yes** (capillary fragility) | No | Yes (coagulopathy) | No | | Corkscrew hairs | **Yes** (follicular hyperkeratosis) | No | No | No | | Poor wound healing | **Yes** (collagen synthesis) | Yes (epithelialization) | No | No | | Recurrent infections | Yes (immune) | Yes (mucosal immunity) | No | No | | Microcytic anemia | **Yes** (iron absorption) | No | No | No | | Bleeding tendency | Petechiae/ecchymoses | No | **Coagulopathy (PT↑)** | No | | Dietary source | Fruits/vegetables | Animal products, liver | Leafy greens, synthesis | Grains, meat | **Clinical Pearl:** Vitamin K deficiency causes **coagulopathy** (prolonged PT, easy bruising with bleeding into joints/muscles), NOT the specific gingival bleeding and corkscrew hairs of scurvy. --- ## Why This Is High-Yield for NEET PG **High-Yield:** Scurvy is re-emerging in India due to: - Malnutrition in low-income populations - Restrictive diets (picky eaters, poverty) - Lack of awareness about fruit/vegetable intake Examiners test: - Recognition of the clinical triad (bleeding gums + petechiae + corkscrew hairs) - Correlation with dietary history - Distinction from other bleeding disorders (vitamin K, hemophilia) - Understanding of collagen's role in multiple tissues **Mnemonic: SCURVY** — Signs of vitamin C deficiency: - **S**wollen, bleeding gums - **C**orkscrew hairs - **U**nhealed wounds - **R**ecurrent infections - **V**essels fragile (petechiae) - **Y**ellow-green bruises (ecchymoses) **Tip:** Always ask about fruit and vegetable intake in a child with bleeding manifestations. Scurvy is rare but classic.