<prompt> A patient of tuberculosis presented with low levels of sodium, chloride and bicarbonate. He also had hyperpigmentation of palmar creases. Most probable diagnosis is: September2008Cushings syndromeAddisons diseasePrimary hyperaldosteronismSecondary hyperaldosteronism  <response>: Ans. B: Addisons disease Primary adrenocoical deficiency Addisons disease More than 90 destruction is required to cause adrenal insufficiency. Autoimmune -80 of cases - Isolated adrenal insufficiency - Type I or II polyglandular autoimmune syndrome Infectious - Tuberculosis - Fungal Histoplasmosis Paracoccidioidomycosis Coccidioidomycosis Cryptococcosis HIV- or AIDS-related - HIV - Cytomegalovirus Mycobacterium avium-intracellulare infection Oppounistic fungal infection - Kaposis sarcoma - Medication effect Metastatic invasion Bilateral adrenal hemorrhage - Associated with sepsis due to Pseudomonas infection or meningococcemia Waterhouse-Friderichsen syndrome - Anticoagulant therapy Adrenal infarction - Hypercoaguable states antiphospholipid syndrome Infiltrative Sarcoidosis - Amyloidosis - Hemochromatosis Hyperpigmentation may be strikingabsent. It commonly appears on elbowcreases of the hand. In advanced stages of adrenal destruction, serum sodium, chloride and bicarbonate levels are reduced and the serum potassium levels is elevated. Hyperkalemia suggests primary adrenal insufficiency, because mineralocoicoid function is preserved in secondary adrenal insufficiency. 