A 32-year-old woman comes to the office due to lightheadedness. She had an uncomplicated vaginal delivery 6 weeks ago with minimal blood loss. The patient had mild fatigue and backache during the last trimester of pregnancy, but the fatigue has worsened since the delivery. She has also been having intermittent generalized abdominal pain, loss of appetite, and weakness. She says her skin is tanning even though she has spent only minimal time outdoors. Yesterday, the patient felt like she was "going to pass out" and experienced several episodes of lightheadedness accompanied by nausea and abdominal discomfort. She has no chest pain, shortness of breath, or bleeding. The patient has a history of hypothyroidism and takes levothyroxine. Her temperature is 36.1 C (97 F), blood pressure is 110/60 mm Hg supine and 85/45 mm Hg standing, and pulse is 104/min. Skin shows generalized hyperpigmentation. Lungs are clear, and her heart rate is tachycardic but regular with no gallops or murmurs. Abdominal examination shows mild, diffuse tenderness without guarding and normal bowel sounds. Laboratory results are as follows: Which of the following is the most likely diagnosis?

Question

A 32-year-old woman comes to the office due to lightheadedness.  She had an uncomplicated vaginal delivery 6 weeks ago with minimal blood loss.  The patient had mild fatigue and backache during the last trimester of pregnancy, but the fatigue has worsened since the delivery.  She has also been having intermittent generalized abdominal pain, loss of appetite, and weakness.  She says her skin is tanning even though she has spent only minimal time outdoors.  Yesterday, the patient felt like she was "going to pass out" and experienced several episodes of lightheadedness accompanied by nausea and abdominal discomfort.  She has no chest pain, shortness of breath, or bleeding.  The patient has a history of hypothyroidism and takes levothyroxine.  Her temperature is 36.1 C (97 F), blood pressure is 110/60 mm Hg supine and 85/45 mm Hg standing, and pulse is 104/min.  Skin shows generalized hyperpigmentation.  Lungs are clear, and her heart rate is tachycardic but regular with no gallops or murmurs.  Abdominal examination shows mild, diffuse tenderness without guarding and normal bowel sounds.  Laboratory results are as follows:  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d39d_be3b_bc81_17d0775e81b4_MD0003_00 This patient has several symptoms consistent with adrenal insufficiency (AI), including weakness, abdominal pain, loss of appetite, and mild hyponatremia. She also has postural hypotension and hyperkalemia, which further raise suspicion for AI. Common in the postpartum period, AI can be due to adrenal (primary AI) or pituitary (secondary AI) disease. Patients with primary AI have loss of glucocorticoid, mineralocorticoid, and adrenal androgen secretion. Symptoms are often severe, and patients may develop significant hypotension, hyperkalemia, and hyperchloremic acidosis. Primary AI is also frequently associated with hyperpigmentation due to increased pituitary secretion of ACTH and melanocyte-stimulating hormone. Autoimmune adrenalitis is the most common etiology for primary adrenal insufficiency and involves both humoral and cell-mediated immune destruction of the adrenal cortex. Up to half of the patients with autoimmune adrenalitis have other autoimmune disorders, which may also flare up in the postpartum period. In contrast to primary AI, patients with secondary AI have only glucocorticoid and adrenal androgen deficiency with preservation of mineralocorticoid production (regulated primarily by the renin-angiotensin system, not the pituitary). Therefore, hyperkalemia, significant hypotension, and hyperchloremic acidosis are not seen. Lymphocytic hypophysitis (lymphocytic infiltration of the pituitary gland) and Sheehan syndrome (pituitary infarction due to hemorrhage/hypotension during labor) are common causes of postpartum secondary AI. This patient has hyperpigmentation and features of mineralocorticoid deficiency suggesting primary rather than secondary AI (Choices C and D). (Choice B) Undertreated hypothyroidism can cause hypotension and fatigue, but this patient's electrolyte abnormalities and hyperpigmentation are more consistent with primary AI. (Choice E) Cardiomyopathy in the postpartum/peripartum period presents with systolic heart failure (ie, shortness of breath, edema). (Choice F) Postpartum endometritis occurs during the first 10 days after delivery, most commonly in patients with prolonged rupture of membranes or cesarian delivery. Typical features include fever, lower abdominal pain, and foul-smelling vaginal discharge. Educational objective: Postpartum adrenal insufficiency (AI) may be due to adrenal (primary AI) or pituitary (secondary AI) disease. Hyperpigmentation and signs of mineralocorticoid deficiency suggest primary rather than secondary AI. References: Adrenal insufficiency. (http://www.ncbi.nlm.nih.gov/pubmed/24503135)

A 32-Year-Old Woman Comes to the Office Due to Lightheadedness