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Prolonged QT interval predisposes to torsades de pointes, a polymorphic ventricular tachycardia that may degenerate into ventricular fibrillation and sudden death. Causes of prolonged QT include congenital syndromes (Jervell and Lange-Nielsen, Romano-Ward), electrolyte abnormalities (hypokalemia, hypomagnesemia, hypocalcemia), and medications (antiarrhythmics, macrolides, fluoroquinolones, antipsychotics). Atrial fibrillation and supraventricular tachycardia involve atrial arrhythmias, not QT prolongation. Ventricular fibrillation may occur as a consequence of torsades but is not the direct complication. Management includes correcting electrolytes, discontinuing offending drugs, and magnesium sulfate for torsades. Congenital cases may require beta-blockers or pacemaker/ICD placement.

Prostate adenocarcinoma is the most common cancer in men. It often presents with lower urinary tract symptoms, back pain, and elevated PSA. Bone metastases are common, particularly to the spine and pelvis, and are typically osteoblastic (sclerotic), distinguishing them from the lytic lesions of multiple myeloma. Benign prostatic hyperplasia causes urinary symptoms but not elevated PSA to this degree or metastatic disease. Bladder carcinoma typically presents with painless hematuria, not sclerotic bone lesions. Diagnosis involves prostate biopsy, and staging includes imaging. Management depends on disease extent and may include surgery, androgen deprivation therapy, radiation, or chemotherapy. Screening with PSA is controversial and individualized.

This patient has Cushing syndrome with low ACTH, indicating an ACTH-independent cause. The most likely source is an adrenal adenoma or carcinoma producing cortisol autonomously. In contrast, a pituitary adenoma (Cushing disease) would present with high ACTH, as would ectopic ACTH production (e.g., small cell lung carcinoma). Exogenous corticosteroid use also suppresses ACTH but typically causes adrenal atrophy. The dexamethasone suppression test helps differentiate: low-dose dexamethasone fails to suppress cortisol in all forms of Cushing syndrome. High-dose dexamethasone suppresses cortisol in pituitary adenomas but not in adrenal or ectopic sources. Imaging is then used for localization. Definitive treatment of adrenal adenoma is surgical resection.

The clinical presentation is classic for impetigo, a superficial bacterial skin infection most common in children. It is characterized by erythematous lesions with honey-colored crusts, usually on the face or extremities. The most common cause is Staphylococcus aureus. Streptococcus pyogenes can also cause impetigo but is less common. Pseudomonas aeruginosa causes skin infections in burn patients and hot tub folliculitis. Candida albicans causes mucocutaneous candidiasis, not impetigo. Impetigo is highly contagious. Complications include post-streptococcal glomerulonephritis, but not rheumatic fever. Management includes topical antibiotics (mupirocin) for localized cases and oral antibiotics (dicloxacillin, cephalexin) for widespread disease.

Adjustment disorder occurs within 3 months of an identifiable stressor, presenting with emotional or behavioral symptoms disproportionate to the event but not meeting full criteria for major depressive disorder. Symptoms resolve within 6 months after stressor removal. In this case, symptoms began after job loss and have lasted 2 weeks, fitting adjustment disorder. Major depressive disorder requires ≥2 weeks of symptoms but without a clear precipitating stressor, or symptoms out of proportion. Persistent depressive disorder involves depressed mood ≥2 years. Cyclothymic disorder involves mood fluctuations for ≥2 years with subthreshold hypomanic and depressive symptoms. Management of adjustment disorder includes psychotherapy, with pharmacotherapy if symptoms are severe or prolonged.