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Looking out for leprosy
,P~tbl t-llth, Lond. (t980) 94,215-218
Looking Out for Leprosy S. G. Browne C.M.G., O.B.E., M.D., F.R.C.P., F.R.C.S., D.T.M.
The Leprosy Study Centre, 57a Wirnpole Street, London, W1 Introduction Leprosy in England is an imported disease. There have only been three indigenously contracted cases in this country this century, and none in the past 40 years. Therefore, looking out for leprosy implies a diagnostic search among people at present resident in Britain (whatever their skin eolour) who have lived some years in a country where leprosy is endemic. Although the dmnces of seeing a case o f undiagnosed leprosy in his consultfilg room wil/occur only once in about 30 professional lifetimes of the average general practitioner, yet leprosy should be remembered in the differential diagnosis of any chronic skin condition that does not resemble a commonly occurring dermatosis, that does nol respond to treatment tha~ should be effective, and especially if it is accompanied b y local and focal disturbance o f nerve function. The ~aumber o f notifications o f cases o f leprosy since t951 (the year that leprosy became notifiable) has now reached 1 I00 and the numbers being notified year by year still exceed 20, notwittLstandin~ the fallin numbers o f immigrants arriving in this country from the medicogeograplfical tropics~ Distribution The distribution o f cases o f leprosy is roughly proportional to the distribution o f the immigrant population, the numbers o f Caucasians with leprosy being almost negligible. Thus, the greatest concentrations are found in London and the Home Counties, Merseyside and adjacent towns, and the Midlands.
Origin Countries of origin o f leprosy patients reflect the proportions o f tile immigrant population coming from countries where leprosy prevalence rates are high. Since the Minister of Health i a a written Parliamentary answer, revealed the countries of origin of leprosy patients now living in Great Britain, it may be assumed that the disclosure o f such information is not banned. Thus, the numbers registered are the resultant of both the actual numbers of immigrants and the prevailing prevalence rates in the countries they formerly inhabited, with the modifying factors o f self-selection and medical screening in the countries of origin.
Sex and Age •Males figure more than females in the notifications-a reflection bofil of the higher proportion • This paper was presented at the Symposium on "'Imported Discuss" organized jointly by the Society of Co~'~munity Medicine and the Royal Institute of Public Health and Hygiene and held at the Wellcome Foundation on 18th March, 1980. 0038-3506/80/040215+04 $01.O0]0
~)1980 The Society of Community Medicine
216
S. G. Browne
of males in the immigrant population and of the higher male: female ratio o f leprosy sufferers in most countries overseas. The age distribution of notified eases accords with the age-structure of the irnmigram popu~,~tion an6 the higher general prevalence rates among adults. Time-lag between Arrival and Notification This is the resultant of several variables: such as, "from the patient's standpoint- the interval between arrival in this country and the reporting of suspicious signs in skin or peripheral nerves (or the hiding of such signs from fear or shame or hope); and from the doctor's point of view the interval between the initial clinical contact and prescription of treatment, and the realization that treatment is ineffective, that the lesions are not typical of a common dermatosis, or that further unusual signs have developed. Sometimes a doctor ,~qth tropical experience, or a doctor reviewing or screening special groups o f people at risk (such as Asians flora Uganda or the Vietnamese "'boa~ people" ) - will strongly suspect leprosy at tlae first clinical contact, but this is unusual. More often there is a time-lag of several weeks or months, or even several years, before suspicion is aroused and further steps are taken to investigate the possibility of leprosy. Thus the fast clinical contact is usually with a general practitioner, thougll an observant or experienced nurse has on occasion noticed some feature about the patient's attitude or symptomatology that has aroused suspicion of leprosy. Once the general practitioner is suspicious, things nowadays take a more rapid course than was the case a few years ago, since the consultant dermatologist -. to whom the patient is usually referred for some "skin trouble" - is more familiar with the clinical presentations of leprosy than lie was a few years ago, has a raised index of clinical suspicion, realizes the need to take a geographical history, and is more conversant with pathological changes in the pigmented skin. Coupled with this is a greater readiness to request the histopathological examination of a skin biopsy. Furthermore, many (if not most) pafl~ologists n~sw think o f leprosy in addition to tuberculosis or sarcoidosis when confronted with a tubercle in the demis, and use acid-fast staining techrdques with greater frequency. Mistakes and delays usually arise because the medical worker fails to think o f leprosy in the process of differential diagnosis, and fails to notice-and to recognize the importance of-slight, or more pronounced, departures from the normal. Since complete openness in giving a history is not typical of those who know, or suspect, that they have leprosy, the practitioner must rely on his own observation and f'mdings when pursuing the quest for a correct diagnosis.
Salient or Significant Features In addition to the general indications mentioned above, certain salient or significant features are so common that they are worth indicating. These are: (1) The clu'onicity of leprosy. The skin lesions are usually very indolent m evolution: they generally change slowly over months rather than days, though rarely some lesions may arise suddenly, and disappear just as suddenly. (2) The remarkable lack of both local and systemic symptoms. The skin lesions themselves itch but rarely, and the general health is unaffected even in the presence o f extensive skin lesions. Spontaneous pain in the peripheral nerves is uncommon in the early stages o f the disease. (3) The combination of lesions in the skin and some impairment o f sensation so very rarely occurs apart from leprosy that leprosy must be considered as the likeliest diagnosis
Leprosy
217
when pigmentary deficit in a localized area is accompanied by some disturbance of sesation. (4) Except in the early stages of any form o f leprosy, some abnormality of ene or more peripheral nerve trunks at a site of predilection is the rule rather th~n the exception. The trunk may be tender on palpation, and perhaps harder than it should be (or, not so frequently, softer), and either larger or (at the late stage) smaller in diameter than normal.
SJgr The presenting signs of leprosy, the signs that bring the patient to the doctor in England, are many and varied. They depend not only on the kind of leprosy and the stage of the disease, but also on the attitude, insight and awareness of the patient. The following combination of signs and accompanying symptoms are the commonest: (1) Skin rash, non-irritating, chronic, simulating other dermatoses (such as a mycosis) or unlike anything known to the doctor. To those familiar with the varied cutaneous manifestations of leprosy, the lesions may be typical and pathognomonie o f the disease. (2) Peripheral nerve damage, shown by impairment of sensation in the lesions and/or in the extremities when nerve trunks are damaged; and by Io~ of muscle power in the muscles innervated by the damaged nerve or nerves. This loss is followed by muscular atrophy. Since the ulnar nerve is by far the most frequently damaged, diminution of sensation in the ulnarinnervated skin and diminuation of power in the ulnar-innervated intrinsic muscles of the hand, and all degrees of claw-hand - main en griffe, main de pradicateur, main de singe, main de cadavre, ntabz succulente - accompanied or followed by muscular atrophy, are the presenting features. The common complaints are of weakness of the grip, and dropping things. Painless burns and scalds occur because hot objects are tounched or held. After the ulnar, the mixed peripheral nerves are usually affected in this order-posterior tibial, external popliteal, median, facial, radial. Any pure sensory nerve, especially when coursing superficially, may be damaged: e.g. the great (or posterior) auricular, the cutaneous branch of the radial, the long sural, the supra-orbital, the supratrochlear, etc. Unnamed cutaneous nerve twigs, e.g. over tile dorsum of the hand, or in the neighbourhood of the knee or elbow, may be affected. Any degree o f loss, and any combination of motor and sensory disturbance, may be found. (3) Impairment of sweating within the skin lesion. The greater the loss o f pignlent within a welt-deff.ued ,area of skin, the likelier the impairment of sweating and of hair growdL (4) Plantar ulceration, resulting from repeated unappreciated traumata to the insenitive sole, perhaps accompanied by drop foot or claw foot. (5) An acutely occurring rash - erythema nodosum leprosum. The patient may have ignored characteristic but asymptomatic skin lesions until such a rash appears suddenly, apparently spontaneously but perhaps precipitated by such conditions as pregnancy or parturition, an Jnlercurrent febrile illness, emotional shock, etc. (6) Some eye trouble, such as mistiness o f vision, or pain, redness, lacrymation or photophobia in one or both eyes. (7) Loosening of the upper central incisor teeth. (8) Testicular pain. (9) Nasa~ obstruction, and perhaps epistaxis or ozaena. Investigation and Management In case of suspicion, the practitioner refers the patient to a consultant dermatologist who either makes ~ clip ical diagnosis at once or takes a biopsy of a skin lesion. The pathologist looks for
2t8
S {7. Browne
~he presence of histopathological changes ie,~icative of one or other kind of leprosy, especially lymphocytic infffllration of.a nerve fibril, and also for the presence of leprosy bacilli. If the changes are typical of tuberculoid leprosy, bacilli are almc,sl never found on standard routine examinatiop~s. On the other hn~-,d,in lepromatot~s or near.tepromatous leprosy, bacilli are generally very abundant. In palieri~s suffering from popar lepromatous leprosy, the nasal mucus (and the nasal mucosa) may contain bacilli in abundance. The consultant dermatologist may call in a member of the Panel o f Leprosy Opinion, or the Consultant Ad~iser to i'fie Department of "l~Iealthand Social Security. lie will notify the ~;ase under confidential cover 1o z~e.Medical Officer for Environmental He~dth. The lepromin ~est is of no value in diagnosis; it indicates ..~,9ote;nti~icell-mediated ,immunity to leprosy infec:ion. It is read at 48 hours (earl3,, Fernandez test), and (more helpfully) at the 3rd week (Mitsuda test). 1~ is comple~e-ly negative in leprornatous leprosy; and strongly positive in tuberculoid leprosy.
Look#~g out for Leprosy thus involves and pre-s,~p.~oses a modicum of.knowledge of the presen'ting signs of leprosy, a raised away:hess o f the possibility of leprosy, and an acquaintance with the procedures necessary to make and to comf'trm the diagnosis. A photokit profile of a typical sufferer from leprosy in this country would be as follows; (a) An adult male; (b) Probably born and lived for several years in a country where leprosy is endemic; (c) More likely to be from the subcontinent of India, or Nigeria or the West Indies; (d) Has been in England from a few days to several years; (e) Has probably had treatment for leprosy in his country of origin. This composite photokit portrait would be an approximation of the majority of patients notified and registered in tiffs country. If general practitioners would look out for him, and luave their aroused suspicions conf'trmed without delay by a dermatologist, then no time would be lost in rapidly reducing the infectivity of the patient to zero and in preventing nerve damage and consequent deformity. Not a big problem in this country and by no stretch of imagination a threat to the general public, but a continuing situation worth tackling wisely and well.
Looking Out for Leprosy S. G. Browne C.M.G., O.B.E., M.D., F.R.C.P., F.R.C.S., D.T.M.
The Leprosy Study Centre, 57a Wirnpole Street, London, W1 Introduction Leprosy in England is an imported disease. There have only been three indigenously contracted cases in this country this century, and none in the past 40 years. Therefore, looking out for leprosy implies a diagnostic search among people at present resident in Britain (whatever their skin eolour) who have lived some years in a country where leprosy is endemic. Although the dmnces of seeing a case o f undiagnosed leprosy in his consultfilg room wil/occur only once in about 30 professional lifetimes of the average general practitioner, yet leprosy should be remembered in the differential diagnosis of any chronic skin condition that does not resemble a commonly occurring dermatosis, that does nol respond to treatment tha~ should be effective, and especially if it is accompanied b y local and focal disturbance o f nerve function. The ~aumber o f notifications o f cases o f leprosy since t951 (the year that leprosy became notifiable) has now reached 1 I00 and the numbers being notified year by year still exceed 20, notwittLstandin~ the fallin numbers o f immigrants arriving in this country from the medicogeograplfical tropics~ Distribution The distribution o f cases o f leprosy is roughly proportional to the distribution o f the immigrant population, the numbers o f Caucasians with leprosy being almost negligible. Thus, the greatest concentrations are found in London and the Home Counties, Merseyside and adjacent towns, and the Midlands.
Origin Countries of origin o f leprosy patients reflect the proportions o f tile immigrant population coming from countries where leprosy prevalence rates are high. Since the Minister of Health i a a written Parliamentary answer, revealed the countries of origin of leprosy patients now living in Great Britain, it may be assumed that the disclosure o f such information is not banned. Thus, the numbers registered are the resultant of both the actual numbers of immigrants and the prevailing prevalence rates in the countries they formerly inhabited, with the modifying factors o f self-selection and medical screening in the countries of origin.
Sex and Age •Males figure more than females in the notifications-a reflection bofil of the higher proportion • This paper was presented at the Symposium on "'Imported Discuss" organized jointly by the Society of Co~'~munity Medicine and the Royal Institute of Public Health and Hygiene and held at the Wellcome Foundation on 18th March, 1980. 0038-3506/80/040215+04 $01.O0]0
~)1980 The Society of Community Medicine
216
S. G. Browne
of males in the immigrant population and of the higher male: female ratio o f leprosy sufferers in most countries overseas. The age distribution of notified eases accords with the age-structure of the irnmigram popu~,~tion an6 the higher general prevalence rates among adults. Time-lag between Arrival and Notification This is the resultant of several variables: such as, "from the patient's standpoint- the interval between arrival in this country and the reporting of suspicious signs in skin or peripheral nerves (or the hiding of such signs from fear or shame or hope); and from the doctor's point of view the interval between the initial clinical contact and prescription of treatment, and the realization that treatment is ineffective, that the lesions are not typical of a common dermatosis, or that further unusual signs have developed. Sometimes a doctor ,~qth tropical experience, or a doctor reviewing or screening special groups o f people at risk (such as Asians flora Uganda or the Vietnamese "'boa~ people" ) - will strongly suspect leprosy at tlae first clinical contact, but this is unusual. More often there is a time-lag of several weeks or months, or even several years, before suspicion is aroused and further steps are taken to investigate the possibility of leprosy. Thus the fast clinical contact is usually with a general practitioner, thougll an observant or experienced nurse has on occasion noticed some feature about the patient's attitude or symptomatology that has aroused suspicion of leprosy. Once the general practitioner is suspicious, things nowadays take a more rapid course than was the case a few years ago, since the consultant dermatologist -. to whom the patient is usually referred for some "skin trouble" - is more familiar with the clinical presentations of leprosy than lie was a few years ago, has a raised index of clinical suspicion, realizes the need to take a geographical history, and is more conversant with pathological changes in the pigmented skin. Coupled with this is a greater readiness to request the histopathological examination of a skin biopsy. Furthermore, many (if not most) pafl~ologists n~sw think o f leprosy in addition to tuberculosis or sarcoidosis when confronted with a tubercle in the demis, and use acid-fast staining techrdques with greater frequency. Mistakes and delays usually arise because the medical worker fails to think o f leprosy in the process of differential diagnosis, and fails to notice-and to recognize the importance of-slight, or more pronounced, departures from the normal. Since complete openness in giving a history is not typical of those who know, or suspect, that they have leprosy, the practitioner must rely on his own observation and f'mdings when pursuing the quest for a correct diagnosis.
Salient or Significant Features In addition to the general indications mentioned above, certain salient or significant features are so common that they are worth indicating. These are: (1) The clu'onicity of leprosy. The skin lesions are usually very indolent m evolution: they generally change slowly over months rather than days, though rarely some lesions may arise suddenly, and disappear just as suddenly. (2) The remarkable lack of both local and systemic symptoms. The skin lesions themselves itch but rarely, and the general health is unaffected even in the presence o f extensive skin lesions. Spontaneous pain in the peripheral nerves is uncommon in the early stages o f the disease. (3) The combination of lesions in the skin and some impairment o f sensation so very rarely occurs apart from leprosy that leprosy must be considered as the likeliest diagnosis
Leprosy
217
when pigmentary deficit in a localized area is accompanied by some disturbance of sesation. (4) Except in the early stages of any form o f leprosy, some abnormality of ene or more peripheral nerve trunks at a site of predilection is the rule rather th~n the exception. The trunk may be tender on palpation, and perhaps harder than it should be (or, not so frequently, softer), and either larger or (at the late stage) smaller in diameter than normal.
SJgr The presenting signs of leprosy, the signs that bring the patient to the doctor in England, are many and varied. They depend not only on the kind of leprosy and the stage of the disease, but also on the attitude, insight and awareness of the patient. The following combination of signs and accompanying symptoms are the commonest: (1) Skin rash, non-irritating, chronic, simulating other dermatoses (such as a mycosis) or unlike anything known to the doctor. To those familiar with the varied cutaneous manifestations of leprosy, the lesions may be typical and pathognomonie o f the disease. (2) Peripheral nerve damage, shown by impairment of sensation in the lesions and/or in the extremities when nerve trunks are damaged; and by Io~ of muscle power in the muscles innervated by the damaged nerve or nerves. This loss is followed by muscular atrophy. Since the ulnar nerve is by far the most frequently damaged, diminution of sensation in the ulnarinnervated skin and diminuation of power in the ulnar-innervated intrinsic muscles of the hand, and all degrees of claw-hand - main en griffe, main de pradicateur, main de singe, main de cadavre, ntabz succulente - accompanied or followed by muscular atrophy, are the presenting features. The common complaints are of weakness of the grip, and dropping things. Painless burns and scalds occur because hot objects are tounched or held. After the ulnar, the mixed peripheral nerves are usually affected in this order-posterior tibial, external popliteal, median, facial, radial. Any pure sensory nerve, especially when coursing superficially, may be damaged: e.g. the great (or posterior) auricular, the cutaneous branch of the radial, the long sural, the supra-orbital, the supratrochlear, etc. Unnamed cutaneous nerve twigs, e.g. over tile dorsum of the hand, or in the neighbourhood of the knee or elbow, may be affected. Any degree o f loss, and any combination of motor and sensory disturbance, may be found. (3) Impairment of sweating within the skin lesion. The greater the loss o f pignlent within a welt-deff.ued ,area of skin, the likelier the impairment of sweating and of hair growdL (4) Plantar ulceration, resulting from repeated unappreciated traumata to the insenitive sole, perhaps accompanied by drop foot or claw foot. (5) An acutely occurring rash - erythema nodosum leprosum. The patient may have ignored characteristic but asymptomatic skin lesions until such a rash appears suddenly, apparently spontaneously but perhaps precipitated by such conditions as pregnancy or parturition, an Jnlercurrent febrile illness, emotional shock, etc. (6) Some eye trouble, such as mistiness o f vision, or pain, redness, lacrymation or photophobia in one or both eyes. (7) Loosening of the upper central incisor teeth. (8) Testicular pain. (9) Nasa~ obstruction, and perhaps epistaxis or ozaena. Investigation and Management In case of suspicion, the practitioner refers the patient to a consultant dermatologist who either makes ~ clip ical diagnosis at once or takes a biopsy of a skin lesion. The pathologist looks for
2t8
S {7. Browne
~he presence of histopathological changes ie,~icative of one or other kind of leprosy, especially lymphocytic infffllration of.a nerve fibril, and also for the presence of leprosy bacilli. If the changes are typical of tuberculoid leprosy, bacilli are almc,sl never found on standard routine examinatiop~s. On the other hn~-,d,in lepromatot~s or near.tepromatous leprosy, bacilli are generally very abundant. In palieri~s suffering from popar lepromatous leprosy, the nasal mucus (and the nasal mucosa) may contain bacilli in abundance. The consultant dermatologist may call in a member of the Panel o f Leprosy Opinion, or the Consultant Ad~iser to i'fie Department of "l~Iealthand Social Security. lie will notify the ~;ase under confidential cover 1o z~e.Medical Officer for Environmental He~dth. The lepromin ~est is of no value in diagnosis; it indicates ..~,9ote;nti~icell-mediated ,immunity to leprosy infec:ion. It is read at 48 hours (earl3,, Fernandez test), and (more helpfully) at the 3rd week (Mitsuda test). 1~ is comple~e-ly negative in leprornatous leprosy; and strongly positive in tuberculoid leprosy.
Look#~g out for Leprosy thus involves and pre-s,~p.~oses a modicum of.knowledge of the presen'ting signs of leprosy, a raised away:hess o f the possibility of leprosy, and an acquaintance with the procedures necessary to make and to comf'trm the diagnosis. A photokit profile of a typical sufferer from leprosy in this country would be as follows; (a) An adult male; (b) Probably born and lived for several years in a country where leprosy is endemic; (c) More likely to be from the subcontinent of India, or Nigeria or the West Indies; (d) Has been in England from a few days to several years; (e) Has probably had treatment for leprosy in his country of origin. This composite photokit portrait would be an approximation of the majority of patients notified and registered in tiffs country. If general practitioners would look out for him, and luave their aroused suspicions conf'trmed without delay by a dermatologist, then no time would be lost in rapidly reducing the infectivity of the patient to zero and in preventing nerve damage and consequent deformity. Not a big problem in this country and by no stretch of imagination a threat to the general public, but a continuing situation worth tackling wisely and well.