A 7-year-old boy with sickle cell disease presents with acute chest pain, fever, and cough. Chest X-ray shows a new infiltrate. All of the following are recognized complications of sickle cell disease EXCEPT:

## Complications of Sickle Cell Disease ### Acute Chest Syndrome (ACS) **Key Point:** ACS is a life-threatening complication characterized by chest pain, fever, cough, and new pulmonary infiltrates. It results from pulmonary infarction (due to vaso-occlusion), infection (pneumonia), or fat embolism from bone marrow infarction. It is a leading cause of death in sickle cell disease. ### Splenic Sequestration Crisis **High-Yield:** Splenic sequestration occurs when sickled RBCs are trapped in the spleen, causing rapid splenomegaly, acute anemia, thrombocytopenia, and hypovolemic shock. This is a medical emergency requiring urgent transfusion. It typically occurs in children under 5 years and is rare in adults (due to autoinfarction of the spleen). ### Osteomyelitis in Sickle Cell Disease **Clinical Pearl:** Patients with sickle cell disease have a 50-fold increased risk of osteomyelitis. Salmonella species are the most common causative organisms (unlike the general population where Staphylococcus aureus predominates). This is a classic association tested in NEET PG. **Mnemonic:** SALMONELLA in SICKLE CELL — both start with 'S'. ### Ocular Complications **Warning:** The most common ocular complication of sickle cell disease is **proliferative sickle retinopathy** (not diabetic retinopathy). Proliferative sickle retinopathy results from retinal vaso-occlusion and neovascularization, leading to "sea fan" neovascularization and potential retinal detachment. Diabetic retinopathy is a complication of diabetes mellitus, not sickle cell disease. | Complication | Mechanism | Clinical Feature | | --- | --- | --- | | Acute chest syndrome | Pulmonary infarction ± infection | Chest pain, fever, infiltrate | | Splenic sequestration | RBC trapping in spleen | Acute anemia, splenomegaly, shock | | Osteomyelitis | Salmonella (classically) | Bone pain, fever | | Proliferative retinopathy | Retinal vaso-occlusion | Sea fan neovascularization | | Diabetic retinopathy | Hyperglycemia (diabetes) | NOT a sickle cell complication | **High-Yield:** Proliferative sickle retinopathy, not diabetic retinopathy, is the characteristic ocular finding in sickle cell disease.