I can diagnose a patient just by looking at them. In medicine, this little trick is called 'the spot diagnosis'. It should be frowned-upon, but we do it out of pride. "Look at me, with my years of knowledge and experience, I know exactly where to pigeon hole you." Yes, it's a bad thing, but it also holds an illicit thrill; all those years of study, and I can do this job. Easily. It's like being able to cook without looking it up in a recipe book first; skiing down a black run with your eyes shut; picking up the phone and knowing who's there before they've even said hello. I can diagnose a patient just by looking at them.
I'm standing on the shoulders of giants of course. Hippocrates was your man back in the day; able to differentiate between diabetes mellitus and diabetes insipidus just by getting his finger dirty. Both present with an increase in the frequency of micturition, but the urine of diabetes mellitus is sweet, because of the body's attempt to dispose of sugar by all means available to it. The urine of diabetes insipidus however tastes of very little, merely the result of the body's incorrect conclusion that as much water as possible needs to be excreted by the kidneys. Many have followed him, adding to this encyclopaedia of knowledge as they go. There are so many obscure eponymous signs, tests and laws in medicine that they become jumbled up in your head; is Buerger's test a method of diagnosing peripheral vascular disease or a gait abnormality? Is a Janeway lesion a sign of infective endocarditis or is that Osler's node? Or is it both? Kernig's sign is a sure way to diagnose meningitis, but what was his technique to elicit it? All of these signs, tests and laws were developed out of desperation. There was no laboratory, no radiology department. You knew all this because you had to know it. Many years of patient observation of patients have elicited these small truths. I'm standing on the shoulders of giants.
So much can be inferred just by looking at the hands. Have you ever been admitted to hospital with an unknown malady? The first thing we always look at is the hands. So much can be seen in them; it's like the body has sent messengers scurrying to the extremities to proclaim its illness. Shake the patient's hand and diagnose dystrophia myotonica when they find themselves unable to let go. I can read your palm and tell you not just your future, but also your now. Palmar erythema in combination with the yellow tinge of your eyes has lead me to diagnose a chronic liver disorder before I've even thought of doing a blood test. Pigmentation of the palmar creases makes me suspicious about the functioning of your adrenal glands. So much can be inferred just by looking at the hands.
A person's nails are pay dirt. I can't even begin to list the types of nail signs that you can see on a patient; and they'll all point you in the direction of a diagnosis. The best sign is that of 'clubbing'. It's hard to describe, but when you've seen it once, you'll always know what to look for. Take their hands in yours and look at the fingers from the side. Do you see? It can be so subtle, but so important that you don't want to miss it: the loss of the angle between the nail bed and the finger. Are you unsure? Compress the nail bed with your own finger and rock it from side to side. Can you feel the sponginess? Then it's clubbing. Of course, sometimes there is no need to palpate; the ends of the fingers are unmistakably enlarged because of the soft tissue swelling. Nevertheless, patients themselves often haven't noticed this. It's amazing what we can fail to notice about ourselves. No-one knows why clubbing occurs, but it is the physician's friend. With it we can diagnose lung cancer, infective endocarditis, inflammatory bowel disease and thyrotoxicosis. A person's nails are pay dirt.
Clubbing can be a sign of:
Reference
- Talley NJ, O'Connor S, 2001, "Clinical Examination: A Systematic Guide to Physical Diagnosis", 4th edition, Blackwell Publishing