Adrenal Insufficiency During Infection
Infection is the most common precipitating factor for adrenal crisis in patients with underlying adrenal insufficiency, particularly gastroenteritis and fever, which can rapidly transform a stable patient into a life-threatening emergency requiring immediate parenteral hydrocortisone without waiting for diagnostic confirmation. 1, 2, 3, 4
Definition and Pathophysiology
Adrenal insufficiency during infection represents a critical mismatch between the body's increased cortisol demand during physiological stress and the inability of the adrenal glands (or hypothalamic-pituitary axis) to meet this demand. 5, 6 This precipitates an adrenal crisis—an acute, life-threatening complication characterized by:
- Cardiovascular collapse with refractory hypotension and shock 3, 6
- Severe electrolyte disturbances: hyponatremia (90% of cases), hyperkalemia (50% of cases) 3, 4, 6
- Hypoglycemia (more common in children) 4
- Altered mental status progressing to coma if untreated 6
Why Infection Triggers Crisis
Infection dramatically increases cortisol requirements through multiple mechanisms: 5, 7
- Cytokine-mediated inflammatory response demands higher glucocorticoid levels
- Fever and systemic stress exponentially increase metabolic demands
- Gastrointestinal infections cause vomiting/diarrhea, preventing oral medication absorption 2, 7
- Sepsis itself directly impairs adrenal responsiveness in critically ill patients 3, 5
The mortality data is sobering: septic shock with documented hypocortisolism carries 26% mortality at 90 days versus 10% when adrenal function is intact. 3 In prospective studies, two deaths occurred during adrenal crisis in a 2-year follow-up of 423 patients. 2, 3
Clinical Recognition During Infection
Suspect adrenal crisis immediately when a patient with known or suspected adrenal insufficiency develops infection plus any of the following: 6, 7
- Unexplained hypotension or shock requiring vasopressors 3
- Profound weakness, nausea, vomiting developing within hours 7
- Muscle/joint pain and drowsiness out of proportion to infection severity 7
- Hyponatremia (present in 90% of new diagnoses) 3, 4
- Anemia and eosinophilia 4
Critical pitfall: Patients already receiving glucocorticoids for other conditions (asthma, inflammatory diseases) may have masked symptoms, making diagnosis challenging. 1, 2 Approximately 7 in 1,000 people on long-term oral corticosteroids—100 times more than those with intrinsic adrenal disease—are at risk. 2, 8
Immediate Management Algorithm
Step 1: Do NOT delay treatment for diagnostic confirmation 1, 3, 8, 7
Mortality is high if untreated—treatment must begin immediately based on clinical suspicion alone. 3
Step 2: Administer hydrocortisone 100 mg IV bolus immediately 1, 3, 8
- Give this before drawing cortisol levels if diagnosis uncertain
- If diagnostic testing needed, use dexamethasone 4 mg IV instead (doesn't interfere with cortisol assays) 1
Step 3: Aggressive fluid resuscitation 1, 8
- Infuse 0.9% normal saline at 1 L/hour (minimum 2 L total) 1, 8
- Volume depletion from aldosterone deficiency (in primary adrenal insufficiency) requires substantial replacement 1
Step 4: Continuous hydrocortisone therapy 2, 3, 4
- Continuous infusion: 200 mg hydrocortisone over 24 hours, OR 2, 3
- Intermittent dosing: 50 mg IV every 6 hours 3
Step 5: Treat the underlying infection aggressively 1
- Broad-spectrum antibiotics for bacterial sepsis
- Source control for surgical infections
- The adrenal crisis will not resolve until the precipitating infection is controlled 1
Special Populations During Infection
Critically Ill/Septic Shock Patients 3
The Surviving Sepsis Campaign and American College of Critical Care Medicine recommend hydrocortisone for patients with septic shock requiring high-dose vasopressors despite adequate fluid resuscitation. 3 Do NOT use ACTH stimulation testing to decide treatment—it delays therapy and doesn't predict who benefits. 3
- Hydrocortisone <400 mg/day for ≥3 days 3
- Earlier shock reversal documented in ADRENAL and APROCCHSS trials 3
Patients on Chronic Glucocorticoids 2, 4, 8
Any patient taking ≥5 mg prednisone equivalent for >1 month has potential hypothalamic-pituitary-adrenal axis suppression. 4 During infection, these patients need stress-dose steroids even if not formally diagnosed with adrenal insufficiency. 2, 4
Cancer Patients 8
Brain tumors, metastatic disease to adrenals, and cancer treatments (surgery, immunotherapy) create multiple pathways to adrenal insufficiency. 8 Surgical episodes are well-documented precipitants. 2, 8
Tapering After Crisis Resolution
Once infection is controlled and patient stabilized: 1, 4
- Taper stress-dose corticosteroids over 7-14 days 1
- Return to maintenance therapy: hydrocortisone 10-20 mg morning, 5-10 mg early afternoon 1
- Add fludrocortisone 0.1 mg/day if primary adrenal insufficiency (for mineralocorticoid replacement) 1
After uncomplicated recovery: double the regular oral hydrocortisone dose for 48 hours; after major surgery, continue doubled dose up to one week before returning to maintenance. 2, 4
Prevention Strategies
Patient education is lifesaving: 8, 6
- Sick day rules: Double or triple glucocorticoid dose during any illness, fever, or physical stress 8, 6
- Emergency injectable kit: Prescribe hydrocortisone 100 mg IM with self-injection training 8, 6
- Medical alert identification: All patients must wear bracelets indicating adrenal insufficiency 8, 6
High-risk comorbidities requiring extra vigilance: 2, 4
- Asthma and diabetes increase crisis risk 2, 4
- Mineralocorticoid-dependent patients are less stable than those with secondary adrenal insufficiency 2, 4
Diagnostic Workup (After Treatment Initiated)
Once patient is stabilized, confirm diagnosis: 1
- Morning ACTH and cortisol levels 1
- Basic metabolic panel (sodium, potassium, glucose) 1
- ACTH stimulation test only if results indeterminate 1
- If primary adrenal insufficiency confirmed: adrenal CT to evaluate for metastasis, hemorrhage, or infarction 1
Distinguish primary from secondary: 1