Aust. J. Derm. (1984)25, 18

AUSTRALIAN ABORIGINES AND PSORIASIS

ALLEN C. GREEN*

Adelaide

SUMMARY

Psoriasis among full-blood Australian Aborigines appears to be rare or absent. Afterexamination of some three thousand of these people in central, northern, and southernAustralia, I have not seen psoriasis. Other medical and nursing observers have also notseen psoriasis In these people. Two references in the literature to psoriasis in A boriginesare reviewed briefly. The author has seen only one, male, part-Aborigine (moreCaucasian than Aborigine), with typical but limited psoriasis. A second example,personally reported to me, was in a female Aborigine whose father was said to be "nottribal". A third was recently reported to me.

Other conditions common among Aborigines, which should not be confused withpsoriasis, are outlined. Certain aspects of the apparent absence of psoriasis in full-bloodA ustralian A borigines are discussed.

Previous research about the essential causes of psoriasis has not been particularlyrewarding. An important question must, therefore, be asked. Should some researchprojects in future be directed to reasons why some human groups seem not to getpsoriasis rather than to why others do?

INTRODUCTION

Since 1960, the writer has carried out derma-tological examinations on some 3,000 AustralianAborigines, predominantly full-bloods. Most ofthese people lived in remote parts of theNorthern Territory. There were lesser numbersseen at remote places in the Kimberley region ofWestern Australia, northern Queensland, andSouth Australia. Psoriasis has not been seen inthose full-blood Aborigines examined.

With two exceptions to be mentioned later,earlier observers did not record psoriasis amongfull-blood Australian Aborigines.'^

The late Professor A. A. Abbie" said he hadnever seen psoriasis in full-blood Aboriginesdespite having examined many. Similar com-

* Visiting dermatologist, Adelaide Children's Hospital andMildura Base Hospital, Victoria.

Address for reprints: Dr. A. C. Green, PO Box 111,Prospect, South Australia 5082.

ments were made by others each with long andextensive medical experience with Aborigines.'"

Three nursing sisters,'""' familiar with theclinical appearances of typical psoriasis inCaucasians, have not seen this condition amongfull-blood Aborigines. Each is well-known to,and highly regarded by, the author for theirknowledge (based on years of practicalexperience) of Aboriginal skin and other healthproblems. Between them they have had overseventy years of accumulated observations.

Between 1960 and 1978, the author visitedover fifty different places in central, northern,and southern Australia. No member of thenursing staff in these places had seen, or knew of,psoriasis among full-blood Aborigines.

Two EARLY REFERENCES TO PSORIASIS

Professor J. B. Cleland, sometime Professor ofPathology at the University of Adelaide, SouthAustralia, wrote extensively on diseases among

AUSTRALIAN ABORIGINES AND PSORIASIS 19

the Australian Aborigines." He made no remarksabout his own observations on psoriasis in thesepeople. In one paper he gave two references topsoriasis in Aborigines. The references, quotedbelow, were:

"Various skin diseases were common, notably pityriasis,psorias* and eczema, besides others in which the exteriorcoating of dirt, grease, and ochre did not permit of accuratediagnosis."'"* The spelling in the original.

". . . the most common diseases are catarrhs, influenza,pneumonia, chronic bronchitis, phthisis, rheumatism, glan-dular affections, inflammation of the kidneys and liver, lum-bago, tabes mesenterica . . . eczematous infections (aspsoriasis, &c).""

Interesting though these early references are,neither can be accepted as evidence of psoriasisamong the Australian Aborigines for two mainreasons. Eirst, the information is neither specificnor detailed. Second, no other observers appearto have recorded psoriasis among these people,among these people.

PSORIASIS IN A PART-ABORIGINE

The only example of psoriasis the writer hasseen among these people was in a part-Aboriginal, male, aged over sixty years. He livedin the north-west of the Northern Territory, Theclinical appearances in this patient, who hadmore Caucasian than Aboriginal features, weretypical and showed plaques of dry, silvery,micaceous scales on the elbows. Histologicalexamination of biopsy material showed thechanges expected in psoriasis. The patient didnot know details of his family history. Theduration of his skin condition could not bereliably obtained. This is a common experiencewhen working with Aboriginal people who donot have a Western sense of time.

CONDITIONS TO CONSIDER IN

DIFEERENTIAL DIAGNOSIS

Psoriasis is usually accurately diagnosed by itsvarious clinical features. These are, as a rule,fairly striking and may even be recognized bysome lay people. Psoriasis of the scalp and nails,in intertriginous areas, and in its pustular andexfoliative forms can sometimes cause diagnosticdifficulty depending on the experience of theobserver and the facilities available.

A personal communication from a practitioner

with extensive dermatological experience^"highlights some of the conditions to consider andsome of the problems encountered in workingamong Aborigines.

" . . . a seventeen-year old, full-blood Aboriginal girl atWarburton, in the central reserves of Western Australia, wassaid to have been recently treated with penicillin as havingyaws . . . she had numerous skin lesions on her lower backand limbs of uncertain duration . . . and extensive crusting ofthe scalp . . . for many years from early childhood. The skinlesions were . . . superficial, slightly scaly, more or lessrounded, and from 1.0-2.0 cm in diameter. They were notcharacteristic of yaws or dermatophytosis. The scalp wasalmost entirely covered with a thick plaqtie . . . at least 0.5cm, through which the hair was growing normally. Theappearance was . . . suggestive of psoriasis. There were nolesions of the nails. Seroiogical tests for syphilis werenegative."

Eive months later, another trip was made byroad to Warburton, some 900 km from the baseat Kalgoorlie. Then it was reported: "The skinlesions had almost cleared. The occipital scalpshowed . . . secondary infection. The girl wasvery sensitive about the . . . condition, andconstantly wore a woollen cap." The patientrefused to be photographed and would not allowany specimens to be taken. A therapeutic trial ofgriseofulvin was suggested. It was not possible tofind out whether this was carried out or to obtainany further information about the patient.

Long distances, difficulties in communication,and Aboriginal attitudes to diseases and theirmanagement, make medical work in remoteAustralia vastly different from that amongCaucasians in the cities. Aborigines can beparticularly self-conscious about a variety of skinconditions. Some examples are ringworm, acne,baldness in males, keloids, and, especially,conditions associated with loss of pigmentation.These days, most Aboriginal patients are willingto allow diagnostic procedures such as takingskin scrapings, hairs, material for biopsy, orblood. A few will not agree to being photo-graphed. They have their own good reasons fortheir refusals and their wishes must be respected.However, in my own experience. Aborigineshave been remarkably co-operative whenapproached about such matters.

YAWS

Yaws did occur among the AustralianAborigines.'- ^ The writer has not seen primary or

20 A. GREEN

secondary yaws among these people. Widespreaduse of penicillin has possibly eradicated thisdisease or reduced its incidence. The hyperkera-totic lesions which occur on the soles and palmsin yaws have also not been seen. However, ter-tiary changes affecting the facial bones andresulting in mutilation and disfigurement(gangosa) will be seen in a few elderly Aborigines.

RINGWORM

Trichophyton tonsurans and T. violaceumIn central Australia and South Australia,

ringworm due to T. tonsurans is common amongAborigines. This dermatophyte frequently causesconsiderable and palpable scaling of the scalp.This is a well-known clinical characteristic ofpsoriasis in which scaling on the scalp is oftenappreciated more by touch than by sight.However, hair loss, usual but not invariable inringworm due to T. tonsurans, is not a feature ofpsoriasis. Hairs affected by ringworm will oftenshow fungous elements on direct microscopy of asuitably prepared wet smear. The dermatophyteresponsible can be isolated in culture.^' ^̂ Ring-worm on the trunk and limbs due to T.tonsurans should not be confused with psoriasis:there may be a discrete, spreading edge but theother margins are usually indistinct and the scaleis not that of psoriasis. T. tonsurans infections inAustralian Aborigines sometimes persist fromchildhood into adult life.''

T. violaceum, another dermatophyte caus-ing endothrix ringworm, is common amongAborigines. It is more usually found in thecoastal regions of South Australia.^'

T. rubrum (granular variant)A granular variant of T. rubrum causes

endemic ringworm among Aborigines living inthose parts of tropical northern Australia wherethe north-west monsoon brings high rainfalls."The associated rash lacks the typical distribution,scales, and other features of psoriasis. Instead,the elements of this ringworm rash are discretepapules, increased pigmentation, more evidentskin lines, sometimes a raised spreading edge, andscales. The clinical patterns seen in T. rubrum(granular variant) ringworm result from different

degrees and combinations of the elementallesions.

Superficial scaling under the waist-band ofshorts or pants is a common appearance and atypical site to be first affected. Scaling can beextensive and resemble that seen in pityriasisversicolor, Norwegian scabies, and exfoliativedermatitis. About 7% of those with ringwormdue to this dermatophyte have infection of thenails either alone or, more usually, in associationwith a suggestive rash on the body. In 273cultural isolations of T. rubrum (granularvariant), only three females (each from GrooteEylandt in the Gulf of Carpentaria), had ecto-endothrix ringworm with partial alopecia due tothis dermatophyte.

Recognition of fungous elements on directmicroscopy of suitably prepared skin scrapings,cultural isolation of T. rubrum from skin andnail scrapings, and the histological evidence inbiopsy material of non-specific inflammationand, in suitably stained sections, of hyphae in thehorny layer, confirm the diagnosis.

PITYRIASIS VERSICOLOR

Occasionally in Aborigines pityriasis versicolorpresents as scaly, sharply dermarcated plaques.These may cause some to think mistakenly ofpsoriasis. However, the affected areas are usuallyhypopigmented, not erythematous, and a simpleskin scraping, examined as a wet smear by directmicroscopy, should soon settle the diagnosis. Themicroscopic examination of skin and nailscrapings for fungous elements and Pityro-sporum orbiculare (Malassezia furfur), thecause of pityriasis versicolor, is made easier bythe following solution.

Potassium hydroxide 60 mlGlycerine 32 mlParker "Quink" (permanent blue-black) 8 ml

Specimens are placed on a glass slide, coveredwith a cover-slip and a drop or two of the fluidfrom an eye dropper or pipette is allowed to rununder the cover-slip. The specimen can beexamined after a few minutes when macerationand staining should have been effected. Theappearances of the yeast-like cells and pseudo-hyphae are diagnostic. They have been likened to

AUSTRALIAN ABORIGINES AND PSORIASIS 21

bunches of grapes on vines and to spaghetti andmeat balls. If a microscope is carried by, or avail-able to, field workers, this test can be quicklydone on the spot. Otherwise, specimens of skinscrapings can be taken or sent to a suitablelaboratory.

SCABIES AND PEDICULOSIS

Scabies and pediculosis appear to have becomeendemic among Australian Aborigines, For thisreason, these conditions must be consideredwhen the diagnosis of a skin condition remainsunproven.

ScabiesWhen Aboriginal patients with the usual form

of scabies first present secondary infection hasgenerally developed.

This is often quite extensive and may deter theexaminer from the diagnosis of scabies. Suchinfection also means that burrows are usuallydifficult to find. Itch (especially when the patientbecomes hot after exertion and at night), thedistribution of the rash, infected lesions, and asimilar affection of other family members andclose personal contacts, should always suggestscabies,

Norwegian scabies has been diagnosed inseveral Aborigines, The diagnosis had beenpreviously overlooked or long delayed. At times,psoriasis had been put forward as a likelydiagnosis. In Norwegian scabies, localized scaly,hyperkeratotic lesions which may be discrete andclearly demarcated, have been a feature. Thescales were hard and not easily removed unlikethose in psoriasis. In addition, wide areas of skincan be red, scaly, and excoriated. Theappearance can be suggestive of exfoliativedermatitis.

The mite responsible, Sarcoptes scabiei var,hominis, is present in large numbers.

DISCOID LUPUS ERYTHEMATOSUS (DLE)DLE has been recognised only recently in

Australian Aborigines living in widely separatedgeographical areas of the continent,̂ "* Thecondition is much more prevalent in these peoplethan among Caucasians in the same areas.

On the upper trunk, there may be sharply

demarcated, scaly, erythematous plaques, whichare usually hypopigmented, Follicular pluggingcan sometimes be seen and occasionally there arekeratin spicules on the under-surface of thescales. The condition may resolve with atrophy,scarring, and loss of pigment. On the face andforehead the lesions are similar. On the scalp,scarring and permanent loss of hair occur. Aninteresting feature of DLE in AustralianAborigines is that the condition may be confinedto the lips. Usually the lower lip is affected,sometimes the upper, and occasionally both,"Biopsy should be done to confirm the clinicaldiagnosis of DLE, Immunofluorescent tech-niques must be used for specimens taken fromthe lips in addition to routine stains.

DRUG ERUPTIONS

Despite extensive use of many drugs, reactionsand rashes do not seem as frequent in Aboriginesas Caucasians, However, from time to time, drugrashes are seen in these people. An epilepticAboriginal male developed exfoliative dermatitis.The drug responsible was phenytoin. Theabsence of a rash before use of this drug, a goodresponse to appropriate treatment, and biopsyindicated the diagnosis.

SYPHILIS

Drug reactions and rashes and syphilis aregreat imitators. As such, they must be regularlyremembered in diagnosis when this is not soonevident.

Syphilis has become common amongAborigines, Papulo-squamous lesions on thepalms and soles, and on the trunk, are fairlyfrequent features of secondary syphilis in dark-skinned people. The Aborigines are no exception.Indeed, the palms and soles should be inspectedas a regular routine. Similarities of appearance insyphilis and psoriasis are well known. However,when dealing with Aborigines, the direction ofdiagnosis should be towards syphilis rather thanpsoriasis.

OTHER CONDITIONS

Ochre on the scalpCeremonial use of ochres by adults and by

children in play may leave a residue on the scalp.

22 A. GREEN

This is not to be confused with ringworm,psoriasis, or other conditions.

Ringworm due to a variant of Microsporumcanis

Microsporum canis (Maningrida type) wasisolated from Aboriginal children living at thesettlement of Maningrida. It was the cause of alocal pocket of endemic ringworm of the scalp.Clinically, there were diffuse or scattered, white,fine scaling lesions with minimal hair loss.Reservoirs of this variant were found in four catsand two dogs at Maningrida.^^

Hyperkeratotic solesAborigines who go barefoot can be expected

to have hyperkeratotic soles and heels as a result.The affected areas are frequently fissured.

DISCUSSION

Racial differences in the incidence andprevalence of various diseases, based on theirgenetic, environmental, and other causes, arewell known. Psoriasis is no exception.

In various English studies, psoriasis was foundin 4.7% of patients in Buckinghamshire and upto 7.0% in Bristol. In Buckinghamshire, psoriasiswas fourth in the "Top Ten" skin diseases with5% of patients seen between 1952-54 having hadthis complaint.^' Other English authorities havesaid that psoriasis accounted for 5-6% of all skindiseases." In Europe psoriasis was said toaccount for 3%-7% of new dermatological cases.In north-western European adults the prevalencehas been given as between 1.5% and 2%.^''

In other parts of the world figures for theincidence of psoriasis show variations:^''

Ibadan (1961-63) 0.5%Jamaica (1966) 1.3%Pretoria (1959-61) 1.45%Shiraz, Iran (1961-62) 3.0%Analysis of dermatological records of a small

series in Tanzania showed that of 230 newpatients, 3.5% had psoriasis.^'

MarshalP' quoted figures provided by anumber of authors for the occurrence of variousskin diseases, including psoriasis. Some of thesefigures are set out in Table 1.

TABLE 1

This shows country, years of observation, incidence ofpsoriasis, basis of figures, and some comments as given by

Marshall

Country&

year

AlgeriaAug. 62-Apr. 63

Egypt1963

Ethiopia1960-62

Angola1954-57

Mozambique1956-60

1956-59

South Africa1959-61

India1960-61

Psoriasisoccurrence

9.2%

3.0%

1.25%

11%(psoriasis anderythemato-squamouseruptions)

3.25%

11.0%(psoriasis anderythemato-squamouseruptions)

1.45%

0.9%3.3%

Comment

514 cases. Psoriasis fourthmost frequent.

2,000 hospital cases. Psoriasistenth of the 10 mostcommon skin diseases.

6,000 cases. Psoriasisfifteenth on the list. Syphilis(23.95%), eczemas (16.8%),scabies (7.8%), were the firstthree.

1,459 Negroes and mulattos.

5,803 Negroes and mulattos.

2,821 whites. (Hospital cases—venereal diseases excluded)

2,000 Negroes (Bantu).

25,381 hospital cases.2,982 private cases.

In one series of 11,729 Negro patients seenbetween 1910-1935, eighty-nine had psoriasis. Itwas pointed out that while psoriasis was morefrequent in white people than Negroes, thiscondition was not as rare in the latter as oncebelieved. However, it was still rare in full-bloodNegroes.^" Psoriasis has been noted asuncommon in Negroes and Japanese but perhapsless rare than formerly thought. The incidence ofpsoriasis in north-west Europeans is higher thanin Africans and Asiatics. The incidence inAmerican Indians is less than in Africans andAsiatics.^' The writer has been told that psoriasisin Eskimos is apparently rare or absent. InMelbourne, Australia, the incidence of psoriasiswas given as 2.57% of 25,296 patients, seenbetween 1938-52 in a private dermatological

AUSTRALIAN ABORIGINES AND PSORIASIS 23

practice." The prevalence of psoriasis in thepopulation of Sri Lanka has been estimated to beover 0.4%."

It is evident that the occurrence of psoriasisamong different racial and genetic groups is quitevariable. Obviously allowances should be madefor differences in diagnostic criteria. However, aspsoriasis is usually recognised on clinical appear-ances by experienced observers, the figures areprobably a reasonable reflection of the incidenceof psoriasis in the series mentioned.

In a brief communication in 1973 the authorreferred to the apparent absence of psoriasis inAustralian Aborigines." After seeing many moreAborigines since then, psoriasis has not yet beenseen in any full-blood Aborigine. In 1982-83, afull-blood Aboriginal female, aged about 60, wasreported by a dermatologist in a personal com-munication to have psoriasis. The clinicalfeatures were typical and the diagnosis wasconfirmed by biopsy. However, subsequentinquiries revealed that the father was 'not tribal',meaning not full-blood.^" The patient lived atPort Augusta about 318km north of Adelaide.A male, part-Aborigine, more other race(s) thanthe Aboriginal, recently required in-patient treat-ment for severe psoriasis.^'

CONCLUSIONS AND QUESTIONS

Psoriasis in full-blood Australian Aboriginesdoes not appear to have been diagnosed, con-firmed, and reported despite extensive medicalobservation by numerous workers over manyyears. The writer knows of only three examplesof psoriasis in Aborigines who are part-Abori-gines—not full-blood. Psoriasis in full-bloodAborigines would, therefore, seem to be rare orperhaps absent. A confirmed diagnosis ofpsoriasis in an Australian Aborigine, who isapparently full-blood, would indicate a need toexclude racial miscegenation. Before Caucasiansand other races settled in Australia theAborigines are believed to have been remarkablyfree from disease except for donovanosis, yaws,t r achoma, hookworm, and r ingworm.Nowadays, poor nutrition, alcoholism, obesity,diabetes mellitus, hypertension, and otherdiseases usually associated with Western 'civili-sation' are increasingly common. Will psoriasis

begin to appear among full-blood Aborigines?And there are other questions. What is the

incidence of psoriasis among full-blood and part-Aborigines? If psoriasis is rare, or even absent, inthese people why is this so? Should not appro-priate research studies be initiated to confirm ordeny the observations made and the questionsraised in this paper? Hopefully, some young der-matologist or geneticist will take up thischallenge.

ACKNOWLEDGEMENTS

My sincere thanks go to the Aboriginal peoplewho were so helpful and co-operative during thetimes I worked among them in remote parts ofcentral, northern and southern Australia.

I am grateful to the medical and nursing staffand others in the Northern Territory MedicalService; to certain members of the staff in theCommonwealth Department of Health in Can-berra and Adelaide; and, to many other people inthe Northern Territory, Western Australia,South Australia, and Queensland who gave methe benefits of their long experience so that Icould enlarge my own.

REFERENCES

1 BreinI, A. (1912): "Report on Health and Disease in theNorthern Territory", Bull. N. T. Aust., 32.

2 BreinI, A. and Holmes, M. J. (1915): "Medical Report onData Collected during a Journey through SomeDistricts of the Northern Territory", Bull. N. T. Aust.,No. 15.

3 Holmes, M. J. (1913): "Public Health Report 1913", N. T.Rep. Admin., 1911-1927:39.

•t Cook, C. E. (1927): "The Epidemiology of Leprosy in Aus-tralia", Commonwealth Department of Health, ServicePublication No. 38, M. J. Green, Government Printer,Canberra.

5Basedow, H. (1932): "Diseases of the Australian Abor-igines",/. Trop. Med. and Hyg., 12:177.

6 Abbie, A. A. (1973): Adelaide, personal communication.'Hargrave, J. C. (1977): Darwin, personal communication.8 Walker, A. C. (1977): Darwin, personal communication.'White, G. E. E. (1977): Alice Springs, personal communi-

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24 A. GREEN

"Smith, Jess. A. (1977): Milingimbi, personal communi-cation.

I'Cleland, J. B. (1928): "Diseases among the AustralianAborigines", J. Trop. Med. and Hyg., No. 5,XXXL:54.

IS Stirling, E. C. (1894-5): "Notes from Central Australia",Intercol. Quart. J. of Med. and Surg., 1:218.

19 Smyth, R. Brough (1876): "The Aborigines of Victoria:with Notes Relating to the Habits of the Natives ofOther Parts of Australia and Tasmania", Vol. 1, JohnCurrey, O'Neil, Melbourne, p. 258.

20 Finger, A. H. (1977): Melbourne (previously Adelaide),personal communication.

21 Donald, G. F. (1959): "The History, Clinical Features, andTreatment of Tinea Capitis Due to Trichophytontonsurans and Trichophyton viotaceum", Aust. J.Derm., 5:90.

22 Green, A. C. and Kaminski, G. W. (1977): "AustralianAborigines and Their Dermatophytes", y4MX/. J. Derm.,1:132.

23 Green, A. C. and Kaminski, G. W. (1973): ""Trichophytonrubrum Infections in Northern Territory Aborigines",Aust. J. Derm., 14:101.

2'! Green, A. C. and White, G. E. E.: "Australian Aboriginesand Discoid Lupus Erythematosus: an Initial Report".In preparation.

25 Green, A. C , White, G. E. E., et al.: "Australian Abor-igines and Discoid Lupus Erythematosus", a secondreport. In preparation.

21'Rook, Arthur, Wilkinson, D. S. and Ebeling, F. J. G.(1972): Textbook of Dermatology, 2nd edition,Blackwell Scientific Publications, Oxford, London,Edinburgh, Melbourne, pp. 26, 27, 1192.

27Sequeira, J. H., Ingram, J. T. and Brain, R. T. (1947):Diseases of the Skin, 5th edition, J. & A. ChurchillLtd., London, p. 226.

28Masawe, A. E. J. (1973): "Psoriasis in Tanzania", Int.Psoriasis Bull., Vol. 1, No. 2.

2' Marshall, James (1964): "Skin Diseases in Africa: an Essayin Epidemiology", Maskew Miller, Cape Town, pp.104-117.

30 Hazen, H, H. (1935): "Syphilis and Skin Diseases inAmerican Negro", Arch. Derm., 316.

3'Summons, J. (1955): "The Incidence of Skin Diseases inAustralia",/I«5/. J. Derm., 3:15.

32 Gunawardena, D. A. et al. (1978): "Psoriasis in SriLanka—a Computer Analysis of 1366 Cases", Brit. J.Derm., 98:95.

33 Green, A. C. (1973): "Australian Aborigines", Int.Psoriasis Bull., Vol. 1, No. 2.

34 Nicolson, June (1983): Adelaide, personal communication.35 Hunter, G. A. (1984): Adelaide, personal communication.