USMLE USMLE-STEP-2 - Questions & Answers

The heliotrope, purple periorbital rash is seen with dermatomyositis and may even precede the muscle involvement. On examination, these patients will usually show proximal muscle weakness and may complain of difficulty getting up from a chair, climbing stairs, and raising the arms over the head. Ataxia may be present with cerebellar lesions. Deep tendon reflexes should be normal and there is no joint inflammation. Polymyalgia rheumatica generally occurs in older people but is not associated with muscle weakness. Spinocerebellar degeneration, vasculitis, and rheumatoid arthritis are not associated with this rash. Creatine phosphokinase is usually markedly elevated and muscle biopsy will confirm the diagnosis.
Serum creatinine, sodium, and potassium should be normal, and the rheumatoid factor should not be elevated.

The heliotrope, purple periorbital rash is seen with dermatomyositis and may even precede the muscle involvement. On examination, these patients will usually show proximal muscle weakness and may complain of difficulty getting up from a chair, climbing stairs, and raising the arms over the head. Ataxia may be present with cerebellar lesions. Deep tendon reflexes should be normal and there is no joint inflammation. Polymyalgia rheumatica generally occurs in older people but is not associated with muscle weakness. Spinocerebellar degeneration, vasculitis, and rheumatoid arthritis are not associated with this rash. Creatine phosphokinase is usually markedly elevated and muscle biopsy will confirm the diagnosis.
Serum creatinine, sodium, and potassium should be normal, and the rheumatoid factor should not be elevated.

Screening should begin approximately 10 years before the age of diagnosis of colorectal cancer in a first-degree (parent or sibling) relative. Given that this patient's mother was diagnosed at age 50, this patient should start screening at age 40. The natural history of a colon polyp to develop into cancer is thought to be 10 years. Colorectal cancer screening has proven mortality benefit.

The presence of effusion generally signifies significant disease. Aspiration of the effusion will help in evaluation for hemarthrosis, septic arthritis, and inflammatory crystal disease. Each of these is important to identify and treat early. An MRI and/or arthroscopy would be later considerations.
Orthopedic referral likely would be necessary.

The x-ray in Figure shows a large, pleural based tumor in the left upper chest; this is most likely a mesothelioma. The tumor is locally invasive, so there are no signs of extrathoracic disease. Direct exposure or contact with asbestos is not required-tumors have occurred in families of asbestos workers. The exposure may be brief and mild, and there is typically a long latent period before appearance of the tumor, about 2040 years. Surgery is curative in local cases. Diffuse malignant mesothelioma responds poorly to all treatments (surgery, radiotherapy, and chemotherapy).

Mitral valve prolapse can be diagnosed by auscultation and echocardiogram in as much as 10% of the population. They may be asymptomatic or complain of atypical chest pain, palpitation, shortness of breath, or weakness. An increasing number of complications are being recognized. Although they occur infrequently, they may be life threatening and demand careful evaluation of individuals at risk. Both supraventricular and ventricular arrhythmias occur, as may sudden death.
Mitral insufficiency, if present, is usually insignificant but may progress and require valve replacement. There is an increased risk of infective endocarditis. Intraatrial thrombus formation may occur, predisposing to cerebral and peripheral embolism. Because the clot originates in the left atrium, however, pulmonary embolism does not occur more frequently in these patients.

The history of severe, self-induced weight loss with an abnormal attitude toward food, weight, and body image in an adolescent female strongly suggests anorexia nervosa. Common symptoms are amenorrhea, not menorrhagia or metrorrhagia, constipation, and cold intolerance. Examination frequently reveals cachexia, hypothermia, bradycardia, hypotension, percarotenemic skin, and increased lanugo-like body hair. Decreased thyroid and pituitary function are evident on laboratory tests, but thrombocytopenia and anemia are not common

Hypercalcemia is a common complication of malignancy. Mechanisms include bone metastases, humoral secretion (e.g., osteoclast-activating factor), prostaglandin, or ectopic parathormone production and immobilization. Hypercalcemia is often manifested by confusion and lethargy. The other metabolic abnormalities usually are not associated with confusion. Therapy is directed at increasing renal calcium clearance and inhibiting further bone resorption. Saline infusion raises the glomerular filtration rate and decreases calcium reabsorption in the proximal tubule. Under life-threatening circumstances, the infusion may need to be aggressive, as much as 6 L of saline daily plus furosemide. Radiotherapy will do nothing for the calcium. Tamoxifen is an antiestrogen used in the treatment of breast carcinoma and other malignancies. When used in the presence of bone metastases, it may contribute to hypercalcemia. Chemotherapy will not decrease the calcium levels. Glucocorticoids have an antitumor effect and reduce tumor production of humoral mediators, but act slowly.

Hypercalcemia is a common complication of malignancy. Mechanisms include bone metastases, humoral secretion (e.g., osteoclast-activating factor), prostaglandin, or ectopic parathormone production and immobilization. Hypercalcemia is often manifested by confusion and lethargy. The other metabolic abnormalities usually are not associated with confusion. Therapy is directed at increasing renal calcium clearance and inhibiting further bone resorption. Saline infusion raises the glomerular filtration rate and decreases calcium reabsorption in the proximal tubule. Under life-threatening circumstances, the infusion may need to be aggressive, as much as 6 L of saline daily plus furosemide. Radiotherapy will do nothing for the calcium. Tamoxifen is an antiestrogen used in the treatment of breast carcinoma and other malignancies. When used in the presence of bone metastases, it may contribute to hypercalcemia. Chemotherapy will not decrease the calcium levels. Glucocorticoids have an antitumor effect and reduce tumor production of humoral mediators, but act slowly.

He should avoid alcohol and spicy foods because these along with the heat, emotional stress, and hot temperature foods can aggravate rosacea. Hydralazine is a vasodilator and could worsen his nasal erythema. Smoking vasoconstricts rather than dilates blood vessels. Metronidazole gel is an effective topical therapy. Laser therapy is usually done after the other interventions have been tried