Important for PLAB
• Please, note that corticosteroids are used after renal transplant for immunosuppression “to prevent rejection”.
• Long-term use of steroids can lead to Cushing Syndrome (high cortisol).
◙ Example,
A child who is obese, short, with abdominal striae with Hx of renal transplant.
√ The cause of these manifestations → Cushing Syndrome (High Cortisol levels) due to exogenous intake of steroids post-renal transplant.
√ The child is short because steroids are Anti-Vit D. Also, high cortisol leads to high blood glucose which inhibits GH (growth hormone).
√ Important features of Cushing particularly in paediatrics →
Moon face, buffalo hump, mood/ behavioural changes, obesity, short, abdominal striae
√ Investigations of Cushing:
- The outpatient screening test → 24 hours urinary free cortisol.
- The best “initial test” to establish the Dx
→ 1 mg (low-dose) Overnight Dexamethasone Suppression Test. - To localise the lesion (to differentiate between pituitary adenoma and ectopic source → High dose dexamethasone suppression test