Introduction

The author is sure that on numerous occasions, experienced clinicians have diagnosed a common disorder and begun treatment only to find that either the patient does not recover as expected or the condition turns out to be something else. This section has been added to this edition to serve as a warning to inexperienced clinicians that things are not always what they seem to be. Physicians always need to maintain a healthy degree of skepticism when they treat a patient for a common disease; there may be an underlying condition or cause that is being overlooked. Where do physicians turn to find out what they could be missing? It is hoped that this section will provide the answer for a lot of cases. It is not intended to include all the possibilities for each condition—just the most common ones.

Acne Vulgaris

A 28-year-old obese white female with a history of seizures has developed a rash on both cheeks. You diagnose acne vulgaris and treat her with a benzyl peroxide preparation and oral tetracycline with poor results. She could have

Cushing syndrome
Reaction to phenytoin
Polycystic ovary syndrome
Impetigo
Sebaceous hyperplasia
Chronic use of oral corticosteroids
Lupus erythematosus
Acne rosacea

Asthma

A 43-year-old white male comes to you with recurrent attacks of shortness of breath, cough, and wheezing for 6 months. You treat him with bronchodilators and corticosteroid nebulizers and he fails to improve. He could have

Congestive heart failure
α-1 trypsin deficiency
Cystic fibrosis
Chronic obstructive pulmonary disease (COPD)
Gastroesophageal reflux disease
Tuberculosis
Pneumoconiosis
Coccidiomycosis
Periarteritis nodosa
Sarcoidosis
Acquired immunodeficiency syndrome (AIDS)
Parasite infestation

Atrial Fibrillation

A 37-year-old white female comes to you for recurrent palpitations. On examination, you find that she has a rapid irregular heart rate and her heart sounds are irregular in intensity also. You should look for

Hyperthyroidism
Alcohol abuse
Hypertensive cardiovascular disease
Collagen disease
Atrial myxoma
Drug toxicity
Cardiomyopathy
Rheumatic heart disease
Coronary artery disease
Drug abuse (e.g., cocaine)
Mitral valve prolapse

Bell Palsy

A 29-year-old black female wakes on the morning of her visit to your office with weakness of the left side of her face and inability to close her left eye. You diagnose Bell palsy and start her on valacyclovir and corticosteroids. What else should you rule out?

Cholesteatoma
Acoustic neuroma
Ramsey–Hunt syndrome
Guillain–Barré syndrome
Mastoiditis
Petrositis
Cerebrovascular accident
Sarcoidosis
Multiple sclerosis

Asthma.

Atrial fibrillation.

Carpal Tunnel Syndrome

A 42-year-old female comes to you because of recurrent weakness and tingling of both hands, worse on the right. Her nerve conduction studies are unremarkable. Nevertheless, you inject lidocaine and corticosteroids into her right carpal tunnel with good results. What else could she have?

Rheumatoid arthritis
Amyloidosis
Acromegaly
Multiple myeloma
Cervical radiculopathy
Menopause syndrome
Hypothyroidism
Collagen disease

Cataracts

A 52-year-old white male comes to you for gradual onset of reduced visual acuity in both eyes. You diagnose bilateral cataracts. What else could he have?

Diabetes mellitus
Myotonic dystrophy
Galactosemia
Acromegaly
Lawrence–Moon–Biedl syndrome

Cholelithiasis

A 12-year-old black girl develops acute colicky right upper quadrant pain radiating to her right scapula with nausea and vomiting. Ultrasonography shows several gallstones, one of which is blocking the cystic duct. What else could she have?

Sickle cell anemia
Diabetes mellitus
Pancreatitis
Congenital anomaly of the biliary tree
Hyperlipemia

Chronic Obstructive Lung Disease

A 48-year-old white male comes to you with a history of heavy smoking and working in the coal mines for 25 years because of increasing shortness of breath and cough, which is no longer responding to bronchodilators and home oxygen. You diagnose COPD. What else could he have?

α-1 trypsin deficiency
Bronchial asthma
Pneumoconiosis
Congestive heart failure
Cystic fibrosis
Bronchogenic carcinoma
Pulmonary embolism
Pneumonia
Tuberculosis
Bronchiectasis
Collagen disease
Pulmonary fibrosis

Cirrhosis of the Liver

A 52-year-old Hispanic male presents to the emergency room in a semiconscious state. Liver function studies show an elevated aspartate aminotransferase, alanine aminotransferase, and serum bilirubin. His prothrombin time and blood ammonia are elevated. You diagnose hepatic coma. What else could he have?

Chronic active hepatitis
Wilson disease
Hemochromatosis
Biliary cirrhosis
Sclerosing cholangitis
Common duct stone with ascending cholangitis
Hepatoma
Collagen disease
Amebic abscess

Congestive Heart Failure

You have just sat down for dinner when you receive a call from an old patient of yours. The man asks if you could “call in” an antibiotic for a “cold” he has had for a week, which is not clearing up. You can tell he is short of breath on the phone, so you decide to make a house call. When you arrive at his home, you note that he is very short of breath and is coughing up frothy, blood-tinged sputum. On examination, he has bilateral crepitant rales, jugular venous distension, and 4+ pitting edema. You diagnose congestive heart failure and arrange for immediate hospitalization. What else should you look for?