The Foot in Diabetes - part 10 pot

In leprosy, as in diabetes, the autonomicinvolvement causing altered skin physiology makes the skin more prone to trauma from stress, bumps or dehydration.. Because of the damage to sens

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22 The Foot in LeprosyÐLessons

for Diabetes GRACE WARRENWestmead Hospital, Sydney, NSW, Australia

``The diabetic foot'' is a term that implies impaired physiological functionthat may result in damaged tissues, ulceration, deformity, destruction andamputations Many of these problems are the result of neuropathy, which isslowly progressive and may be ®bre-selective, with pain ®bres frequentlyaffected early, well before there is clinical loss of touch or pressuresensation It is often unaccompanied by de®nite symptoms, so that manypatients do not realise that a neural de®cit is developing until they areconfronted with ulceration or other resultant problems

A similar problem may occur in leprosy, in which the nerves areparasitized early without any symptoms Over a period of many years theremay be increasing ®brosis and slow loss of neural function until the limb istotally neuropathic, motor and autonomic as well as sensory The sensoryneuropathy is the main problem, allowing the possibility of unnoticed andhence untreated trauma because the patient does not have enough painperception to demand care The resultant problems are virtually the same asthose seen in diabetes In leprosy, as in diabetes, the autonomicinvolvement causing altered skin physiology makes the skin more prone

to trauma from stress, bumps or dehydration

Together with many other neuropathies, these diseases have severalproblems in common The most important is the so-called ``non-healingulcer'' In 1877 John Hilton1wrote: ``pain was made the prime therapeuticagent After injury, pain suggested the necessity of, and indeed compelledThe Foot in Diabetes, 3rd edn Edited by A J M Boulton, H Connor and P R Cavanagh.

& 2000 John Wiley & Sons, Ltd.

The Foot in Diabetes Third Edition.

Edited by A.J.M Boulton, H Connor, P.R Cavanagh

Copyright  2000 John Wiley & Sons, Inc ISBNs: 0-471-48974-3 (Hardback); 0-470-84639-9 (Electronic)

man to seek for, rest'' Because of the damage to sensory nerve pain ®bres,these patients lack the natural sparing re¯ex that makes man seek for that rest.

In the middle of the twentieth century, large institutions providedprolonged outpatient care for thousands of leprosy patients and residentialcare for hundreds who lived in these institutions for many years Thisprovided an excellent opportunity for studying the effects of all degrees ofneuropathy and of observing the results of neglect and the effects ofmethods of management

Previously, it was assumed that the ulcers of leprosy patients were part ofthe disease and would never heal However, with the introduction ofeffective bactericidal drug therapy, it was realised that these ulcers were notpart of the disease itself but were mainly due to the loss of pain perception

Dr Paul Brand, working at the Christian Medical College Hospital inVellore, South India, in the late 1940s, was challenged with the question,

``Why do ulcers continue to occur when the disease is cured?'' He did notknow; no-one knew He gathered around him a group of researchers whoplayed a major role in identifying the reason for continuing ulcers anddetermining methods of management that literally save hands and feet, notonly of leprosy patients, but of persons with neuropathy from any cause.The story of the battle to understand the problem of ``no pain'' is afascinating one of how many people, working together, eventually solvedthe problem of why neuropathic ulcers appear not to heal2 The under-standing we now have, and the methods that we have been using forleprosy for over 40 years, stem from this research In the last 40 years I havebeen asked to treat neuropathy from many causes and I have found that thesame methods are effective, irrespective of the cause of the neuropathy3.The principles laid down by Dr Brand and his colleagues are still applicableworld-wide in saving limbs and improving the quality of life of those whohave damaged nerve function from any cause

In diabetes, as in leprosy, there are often no characteristic symptoms thatindicate that a nerve de®cit is developing Hence, the patient may notrealise that the ability to feel pain has been lost until some accident occursthat results in a lesion that is surprisingly painless This may be a burn, ablister or a fracture The common factor is that a lesion caused by trauma isneglected because it is painless and the patient does not automaticallyrespond by protecting the traumatized area, and hence the lesion maybecome a non-healing ulcer However, in leprosy it had been shown that if

an affected limb was completely rested, ulcers healed4as quickly as similarlesions in a sensate limb This understanding resulted in the use of totalcontact casts5, which encouraged healing by preventing excess pressure onthe traumatized areas but enabled the patient to continue walking

Special testing of nerve function is often requested following examination

of the patient Nerve conduction studies may show the speed with which an

impulse travels along a nerve, but do not tell what information thoseimpulses pass to the brain Many patients with neuropathy haveparaesthesiae, but what do those paraesthetic feelings indicate? Is thebody trying to indicate what a person with normal sensation would interpret

as pain? It is the ability of perceiving pain as pain that is the important factor.Hence, electrical testing may give false ideas of the patient's ability to protecthim/herself Loss of pain perception is the biggest problem The use ofSemmes±Weinstein mono®laments6to test skin sensation is helpful to chartvariations in neural function But it is not a measure of protective sensation,

as it does not test for pain perception A patient may have normal perception

of a 10 g ®bre but have no discomfort when a sliver of glass cuts the foot Thewisest rule is to treat any patient with any suspicion of neuropathy as thoughthere was complete loss of sensory perception and to start teaching thepatient self-care as soon as neuropathy is suspected

Leprosy patients may show marked motor and autonomic nervedysfunction, even when there is little obvious sensory de®cit5 It is advisedthat multiple neuropathies be assumed to be present whenever any neuralde®cit is detected Over the past 40 years the writer has managed patientswith neuropathy from many causes, using the same principles as thoseindicated by Coleman and Brand7 Teach the patient how to protect the limbs asthough there was no sensation at all The patient may say that feeling is present,but who can know exactly what that patient means by ``feeling'' Is itparaesthesia, numbness or one of a multitude of feelings, such as ``burning'',

``cutting'', or ``compression'' that do not include protective sensation and donot provide the stimulus needed for the patients to protect themselves? Manypatients say they have pain but describe what may be ``tingling'', or ``pins andneedles'' that may be due to abnormal nerve activity and may even indicateregrowth of damaged nerves Young patients may call this ``pain'' becausethey have no previous experience of real pain It is advisable to inquire intothe quality of ``pain'' and perhaps record the feelings as discomfort ratherthan pain If deformity and disability are to be prevented, it is essential thatthe patient realises that there is a de®ciency in sensory perception

Our work with leprosy patients brought to our attention other problemsarising from nerve de®cits that may be relevant to diabetic patients Theinvolvement of motor nerves may result in clawing of the toes which, inturn, causes excessive pressures over proximal interphalangeal joints and

on the plantar surface of the metatarsal heads In diabetic patients this isoften dealt with by orthoses and moulded shoes These have also been used

in leprosy patients, but it was found that surgery8, such as that forcorrecting clawed toes or a dropped foot, could correct the problempermanently This could eliminate the constant need for new footwear bystraightening the toes yet leaving them mobile, ¯exing the metatarsal jointsand so spreading the stresses of weightbearing It reduces the risk of

The Foot in LeprosyÐLessons for Diabetes 347

ulceration The excessive stresses caused by muscle imbalance in the lowerlimbs may stimulate excessive callus formation and may result inulceration In leprosy, many of the consequences of muscle imbalance areminimized by tendon surgery and, in my experience, these procedures arejust as effective in neuropathy from other causes9and have often resulted inthe salvage of a limb that might otherwise have been amputated.Unfortunately, it is uncommon for diabetic patients to bene®t from thistype of surgery, although for the diabetic patients on whom I haveperformed reconstructive surgery, the results have been well worthwhile3.

In leprosy patients a large proportion of ulcers originate under callus orscarred skin This callus, if not regularly removed, builds up and forms a thickmass, some of which dehydrates and becomes very hard If on the sole, thismay cause excessive pressures in the deeper tissues during walking and result

in ulceration A similar situation exists in diabetes10and other neuropathies9.After removal of the callosity, leprosy patients are taught to rub oil into the area

on a daily basis, which keeps moisture in the skin, preventing dehydration3.Skin treated in this way improves in texture and resilience and, by becomingless fragile, is better able to withstand trauma The same principles have beenapplied to patients with diabetes presenting with dry, fragile skin Regularrehydration and oiling results in improved smoothness and suppleness andability to withstand the stresses of daily use Rehydration and oiling help tocompensate for the effect of autonomic neuropathy on the sweat andsebaceous glands when the secretion of both sets of glands may be greatlyreduced or completely lost Brand4 observed that feet that sweat normallyrarely become ulcerated and that rehydration is possible In 1966, Harris andBrowne11 published observations showing that the application of cosmeticmoisturisers alone did not improve skin quality, but soaking in water,followed by oil, was effective as long as it was continued regularly Tovey10suggested that, for diabetic patients, oilatum emulsion be added to the waterused for soaking dry skin and aqueous cream be rubbed into the skinafterwards

There are an estimated 15 million people affected by leprosy in the world,mostly in areas where there are minimal medical facilities, and it wasnecessary to devise treatment plans that patients could do themselves atminimal cost The following daily routine has been taught in many areas sothat the patient provides his/her own home care3

DAILY CARE FOR PERSONS WITH NEUROPATHIC LIMBS

It is important to teach all patients who are suspected of havingneuropathy to start daily care as soon as possible in order to maintain

the affected areas, especially the feet, in good condition This teachingshould be given by demonstration Do not just tell the patients; showthem how and then get them to do it themselves so that they reallyknow how to continue at home3 As the feet are the most likely areas to

be affected, the care of the feet will be described but the principles can

be adapted to other areas of the body

1 LOOK at their own feet every day, preferably at night, so that anywounds can be treated that night If they cannot see the sole of the footthey can use a mirror or arrange for a partner or carer to do it for them.Their feet and shoes should be inspected by a staff member every timethey attend clinic This helps to impress importance of foot care uponthe patients and their relatives and may reveal trauma that has beenconsidered unimportant Many patients have stated, ``my feet are ®ne'',yet painless lesions are found on removal of shoes and socks

2 SOAK the feet and legs in plain water every day This remains acontroversial point in diabetes but is used by some clinicians treatingdiabetes10 In leprosy, as stated above, it has been shown time and timeagain that soaking is bene®cial5 Dryness is very obvious when peoplewalk barefoot or wear open sandals, and a dry atmosphere constantlyincreases the dehydration of the skin In leprosy clinics it has beenobserved that healing occurs more rapidly on ulcerated feet that aresoaked daily and in which dehydration is prevented by oiling, than inthose feet that are left dry The application of moisturising creams andlotions does not actually rehydrate the deeper layers of dry skin Theymay improve hydration of super®cial layers and reduce furtherdehydration, hence they keep in what water there is and make theskin feel moist for a period

3 SCRAPE off hard, dry or rough callus that may irritate or increaselocal pressure: smooth dry hard callus splits and cracks, traumatizingtissues Most patients can learn to keep callus under controlthemselves at home (in the case of those visually impaired, arelative can do it for them) However, this is controversial and not allauthorities recommend self-care of callus in neuropathic patients Ifthe clinician or podiatrist commences by removing the excessiveamounts of callus, it should be possible for the patient to prevent anew build-up of callus However, it is still advisable for the patient

to visit the podiatrist regularly to ensure that new masses of callus

do not build up Many patients have used a pumice stone or nylonpot scraper which, to be effective, needs to be rough Othercommitments often mean there may be long intervals between visits,allowing excessive amounts of callus to develop unless the patientcan help by doing a little every day

The Foot in LeprosyÐLessons for Diabetes 349

The ®rst time a patient is seen with an ulcer surrounded orcovered by callus, it is essential that the callus be removed in order

to determine the size and severity of the ulcer3 The pressures caused

by localized masses of callus are one of the most likely causes ofulceration in the insensate limb and the patient needs to understandthat thick, dry, hard, irregular or cracked callus causes problems

4 OIL the skin to keep the water in Any oil or moisturising cream will beadequate to help prevent evaporation and dehydration There isevidence that ®sh oil or animal oil, such as lanoline, may be absorbedand improve the quality of the skin as well as keeping it hydrated, andthese oils are often rubbed in regularly to improve quality of scars afterburns

5 DRESS WOUNDS with simple dressings to keep them clean Expensivedressings have no advantage over saline, simple ointment, Ungvita orMagnoplasm3 Most neuropathic wounds will heal with anything onthem except the patient's weight! It is not the dressing that heals theulcer The ulcer will heal if it is kept clean and protected from furthertrauma Pressure on an ulcer causes local anoxia and this damages thehealing tissues

6 PROTECT from trauma If there is no wound or ulcer on the limb,proper protection would be the wearing of suitable footwear and theuse of other protective appliances If there is trauma or an ulcer on avulnerable site, some form of splinting or other protection should beinstituted once the dressing is in place

7 EXERCISE to maintain mobility of ankles, toes and hands, and to gainoptimal ef®ciency of any functioning muscle

THE ORIGIN AND TREATMENT OF ULCERS

How do ulcers start7? The initial ulcer is usually the result of primarytrauma It may be due to:

1 Sudden very high pressure, as when jumping from a height, or stepping

4 Burns, cuts, bruises and friction

Once an ulcer has healed, an area of scar will remain that will be moreprone to trauma than normal tissue