Thursday, 10 July 2008

Why Are The Hands So Important?

Dear Bloggers

Today I want to go over why I think the physical examination of the hands is such an important part of the general physical examination.

Without a good look at the hands, one can sometimes miss the diagnosis that might otherwise take a long time to make via other means.

After standing at the end of the bed to observe the general appearance of the patient, I advise to then look at the hands.

Check the nails-- these are like the looking glass into the body. Digital Clubbing is a great sign to find and can help to narrow your differential diagnosis significantly. Please see my previous posting on this topic of clubbing here.

One can also see the arrest of nail growth referred to a Beau's Lines, which are horizontal indentations in the nails. One can accurately date the onset of serious illness by measuring the distance in millimeters from the Beau line to the edge of the nail fold. The nail grows approximately 0.1 mm / day. Hence, for example, a distance of 5mm would equate to onset of illness dating back 50 days or just under 2 months.

Muehrcke's Lines are paired white lines without indentation that are seen in the nail in patients with hypoalbuminaemia, post-chemotherapy etc.

Splinter haemorrhages, which are outlined in my previous blog entry linked above, are a fascinating phenomenon which may indicate infective endocarditis. They are not a pathognomic feature because they can also be caused by trauma to the nail. Hence, if you see them, don't just consider I.E. Ask the patient if they do gardening or some other hobby or employment that exposes them to nail trauma. However, more than 6 is significant for considering I.E.

Koilonychia (spoon nails) is the famous sign of iron deficiency anemia. However, never forget to look at the corners of the mouth for red, painful areas which is known as angular cheilosis. The tongue may be affected by atrophic glossitis (inflamed). Problems with swallowing should alert you to the rare post-cricoid web which can become cancerous. The presence of the latter with IDA is referred to in the UK as the Plummer-Vinson Syndrome and in the USA as the Patterson-Kelly-Brown Syndrome. Both identical syndromes were described at approximately the same time in the two English speaking continents!

Looking at the nail folds is very important. Sometimes, nail fold infarcts can be visualised as is the case in rheumatiod vasculitis and several other vasculitic disorders. Moreover, if one looks closely at the nailfold proper, seeing capillary loops may signify systemic lupus erythematosis (SLE)! Yes, just from looking at the nailfold!

As I documented last week, Quinke sign can be found in the nail in the area of the interface between the white and red areas of the nail. It can also be found in the skin-- ? B−sign :-)

Nails can also be affected by psoriasis and take on several features including:

  • Subungual hyperkeratosis (thickening of the nail)
  • Onycholysis (lifting off of the nail)
  • Nail pitting (looks like the indentations on the surface of a thimble)
  • Nail ridging
In the UK exams, they may sometimes just show the doctor the patient's finger nails and ask for the diagnosis without showing the patient's skin. Psoriasis would be the right answer.

Looking at the tips of the fingers can reveal the tender Osler Nodes (small lymph nodes) of I.E.

One might also be able to identify the skin colour changes of Raynaud's Phenomenon.

Tightening of the skin of the fingers is a sign of possible systemic sclerosis.

Of course checking for diffuse synovial swelling, joint swelling, joint pain and deformation is important and part of the rheumatological examination and diagnoses of RA, osteoarthritis, gout, etc, can be made in addition to the unusual Complex Regional Pain Syndrome which can mimick rheumatic disease.

Looking at the palm of the hand may reveal thickening and shortening of the 4th and 5th tendons that one sees with Dupytren's contracture, the cause of which is usually due to alcoholic liver disease, although other causes include
  • Use of heavy, vibrating machinery e.g. drilling tools
  • Peyronie's disease
  • AIDS
  • Epilepsy (due to drug treatment)
The palm may also reveal Janeway lesions of I.E., and hence, this is another very important place to observe for signs of this serious infection.

Palmar erythema (red palms) is another helpful sign as it may signify one for the following
  • Liver disease
  • Thyrotoxicosis
  • Rheumatoid arthritiis
  • Pregnancy (the distended abdomen usually gives you a better idea :-) )
Checking the lines in the palms may reveal hyperpigmentation which is consistent with increased output of ACTH e.g. Addison's disease, ACTH secreting tumour; obviously, this depends upon the race of the patient as it is easier to identify in lighter skinned individuals.

Ask the patient extend their arms and fully extend the palms with open fingers to look for the sign of asterixis (flapping tremor) that one can observe in
  • Hepatic encephalopathy
  • CO2 retention
  • Uraemia
Checking for muscle loss in the hand e.g. thenar eminence, may give you a clue about median nerve impairment whether it be an entrapment in the carpal tunnel (check Phalen's and Tinel's tests for that) or higher up in the arm / cervical area.

Checking the muscles on the dorsum of the hand (Dorsal interossei) can signify a motor neuropathy, myopathy, or malnutrition if bilateral and diffuse. However, be warned, unilateral dorsal interosseus muscle wasting in a smoker can signify the presence of a Pancoast tumour.

Other neurological signs can be found in the hand which include the fine tremor of thyrotoxicosis, the pill-rolling tremor and cog-wheel rigidity of the wrist in Parkinson's disease. Hoffman's Sign, flicking the nail of the middle finger in a downward motion leads to the flexion of the index finger and thumb, which signifies an upper motor neurone lesion.

The last and widely neglected part of the physical examination is taking the radial pulse. This is truly essential. One must assess the heart rate, rhythm, and volume quality. The first two are relatively easy to understand. The third essential element requires experience in understanding the normal pulse and being able to understand the abnormal.

The patient with a high bounding pulse which collapses may well have aortic regurgitation or a vascular shunt e.g. portocaval anastomosis in liver failure, dialysis shunt. On the other hand, the pulse may be slow to rise which signifies advanced aortic stenosis.
A jerky pulse may signify hypertrophic cardiomyopathy.

The low volume pulse can be found in patients with poor cardiac output, hypovolaemia e.g. vascoconstriction, and is described as thready.

Hence, as can be appreciated, there is a vast amount of information that can be gleaned from examining the hands.

For a more in depth explanation and to see pictures of the examples I have given above, please see a good physical examination book. I would highly recommend MacLeod's Clinical Examination, which has 424 pages with detailed colour illustrations and is published by Churchill-Livingston which is obtainable from Amazon or other good book sellers. I used an earlier edition for aiding my learning of physical examination as a student, and I consider it as an excellent book for this medical art. In my opinion, it is better than the various 'famous' USA physical examination books that are promoted in Japan.

Hence, please start looking at the hands. You will be amazed what you may find.

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