Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 5-1-1970 Studies on the distribution and habitat of Demodex folliculorum Michael James Gimbol Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Let us know how access to this document benefits ou.y Recommended Citation Gimbol, Michael James, "Studies on the distribution and habitat of Demodex folliculorum" (1970). Dissertations and Theses. Paper 58. https://doi.org/10.15760/etd.58 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. AN ABSTRACT OF TILE THESIS OF Michael Jam·es Gimbol for the Master of Science in Biology presented May 2Z, 1970. Ti t If3 ~ Stttd i es on the Di s t r ibt1. ti on .and Hah i tat of De.!"!,:..oc0!.?i foll iculor-tur.. • ..........-..-.~ .......------~ APPROVED BY ~ilEl\;ffiERS OF THE; THES IS C01VIJHl TTE.E;: :.o;....-.,.,~""tJl ---.............. ~··_~ ..····~ . ..__ Richard B~ Forbes ="9 - , The present study was undertalcen to determine the Derr.:..c:~l ~ 9~:~!_~Tl1~. inci dence of i nfestation \vi til € f 01 i j a s lei. n mite parasitizing man, and to investi.gate those factors' which influence its occurrence.. These factors were the personal hygiene, sex, age a.n.d. skin conditIon ()f the human host~ A detailed view of the habitat of this parasite is also included so that the controversy 8urrotu"1ding its I'ole as a possible pathogen or vector of disease could be explored in 1i ght of the current }(11,O\;v!ed ge o(l A ntnnber of si tes of infestat.ion were sampled by a 2 number of different techniques. The primary sample site was the nasal area of' the face \vhich was .examined by slit lamp magn~fication after chemical application to partially expose the mi tes. A secondary 51 te involved the eyelash follicles from which the lashes were epilated and examined for mites under the microscope. l'he 441 sUbjects examined.· in the nasal area were tabulated by age, sex and skin condition and the incidence ·of i.nfestation. wa.s computed for each of five age groups. 'Ther~ was a definite increase in incidence of _._-Demodex with the advancing age of the host and the normal and oily skin conditions appeared to be much more involved than the dry skin condition. A similar increase in incidence with advancing age was apparent in the 1.43 'subjects whose eye­ lashes were examined. \. The res ul ts from both areas exhi bi ted a statistical correlation between the age and skin condition of the hmnan host and the presence of mites. The explanation of the increase in incidence with the advancing age of the human host is based on the development and secre tory rate of the s ebaceous g1 ands of the human hoste Past studies have shovm that Demo~e~ lives in and around the sebaceous glands of the skin and feeds on sebaceous material and cellular debris. The face appears to be the habitat of optimum occurrence which corresponds to the d~stribution of sebaceous follicles and glands whose size and rate of secretion are greater than those over most 3 of the body_ The role of -Demodex in the formation of ingrown hairs on the neck is di.scussed as a possible, new on demodectic infestation remains rather obscure. Although -the accumulation of sebaceous materi~l would tend to favor the maintenance of mites, the reservoirs of the sebaceous follicles of the face in Which the mites are found are not effected by normal soap and water cleansing. Inhabitation of the eyelash follicles may be enhanced by ineffective 'bleansing~ but more study is needed to determine the validity of this contention. The finding of selective sites of in.festation on the "human host led to speculation on the possibility of physiol~ ogica1 races of Demode~e Although it is difficult to determine the validity of reports by earlier workers" there appears to be a decreas- ing trend in the incidence of Demodex fol1iculorum sincB ---....-.-- ,...".....-~--_.. ,-- its discovery over a century ago. S1UDIES ON TIlE DISTRIBUTION- .l\.ND lil\BITAT OF P~jDDEX FOLLICULO~ by MI CRlLEL J.AI\!1ES GIMBO L A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF· SCIENCE in BIOLOGY Portland State University 1970 DaTLAND STATE .UNIVERSITY LIBRARY TO THE OFF ICE OF GRADUATE STUn IES : The members of the Committee approve the thesis of' Michael James Gimbol presented May 2Z, 1970. -' Richard B. ForDcs ..t\PPROVED : Earl Fisher, Jr., He-a~d~,~D-epartment of Biology May 22 , 1970 ACKNOWLEDGMENTS There are many people to whom I am profoundly grateful for the assistance they have given me in this thesis. I am espe,cially indebted to Dr. Ralph w. Macy as my thesis adviser, for his help with the photographio work included in this thesis, and for his consistent encouragement; to Dr. Riohard B. Forbes for his un­ stinting faith in me and my work and for advising me throughou.t my graduate program; to Dr. Earl Fisher, Jr., for his help in obtaining equipment for this study and for the support of an assistantship through his offioe; to Dr. Quentin Clarkson for his generous help in the statistical analysis of the data; to Dr. Robert P. Burns, from ,the Opthamology Department of the Univers.ity of Oregon Medical School, for the loan of a slit lamp from his i laboratory without which this study would not have been possible; a~d to Dr. Clyde L. Calvin for the use of his mi~photographio equipment and his expert advice in processing the photographs. -~ TABLE ,OF CONTENTS j PAGE ACKNOWLEDGMENTS • •• • •• • • • • • • • • ... • • iii LIST OF TABLES ••• • • •• • • • • • • •• • • • v LIST OF FIGURES • • • • ••• • • • • • •• • •• vii INTRODUCTION • • • • • '. • •• • • • • • • • • • • • 1 MATERIALS AND METHODS • • •• •• • • • • • • • • • 12 RESULTS • • • • • • • •• • • • • • • • • • • • • 20 DISCUSSION ~ • • • • • ------• • • · ~ • • • • • • • • • • 33 REFERENOES CITED • • • • 64 •• • • • • • • • • • ·. • • ADDITIONAL REFERENCES • • • • • • • • • • • • • • • 68 ~ ----J ~ ~ ~ d -i LIST OF TABLES TABLE PAGE Measuremen ts of D~mocJex. FoIl i.SE-.lo~~.t1l from Hi rs.t (1.919) ••••• • • • tJ 8 II Incidence of Demode~fol1i~~1:~~in Normal and Disease States in Man. ~ 10 III All Pertinent Data From Nasal Area Examinations • • ••• ••• • • • 21 IV Sex of the Hos t and the .Incidence of Dernodex • 22 -~--- •• • • • • • • • • • • • V Contingency Chi-square Results from Na~al Area Examinations •• e • • • VI Results from the Cheeks and Chin Uti liz- ing the Chemical Slit Lamp Tech- nique •••• • • 0 • ~ •••••• 25 , VII Results of Preliminary Eyelash Test _ . .=5 Conducted on Se lee ted Group uf Forty Subjects •••••••••• 29 VIII Resul ts from Epi lating Eyelashes 'of 143 Subjects ••••••••••• 30 IX Results from Squeezing Facial Follicles of the Nose and 'Forehead Regions •• 30 .... vi TABLE PAGE x Results from Pustule Contents of Ingrown Hai rs on the Neck •. •• •• 31 XI Results from Epi1ating Hairs from the Chest and Pubic Areas ••• • ••• 32 XI.I Result~ from Ear Wax.Scrapings ••••• 32 XIII' Cases in \Vhich Demodex fo1licu1orum Bears a Suspect Causal or Cooperative Rel~tionship ••••• 59 LIST OF FIGURES FIGURE PAGE 01 Drawings of pemodex fol1ic~!orum, Drawings of ~~deX fo11icu1o~~ Larva, Nymph, and Adult, and ~2dex ~J.is_ • 6 3 Egg and Larvae of Demodex fol1iculorum •• 7 ..... , ...... -.... ..----......_~ .. 4 Bah i tat of Demo~ _:t~!.!a~...cul OI't.!..f!! e • \l • e 0 13 5 Views of the Eyelashes Showing Debris and Collaring Ab out Lashes oWhich is Characteristic of Demodectic Infesta- ~i on ••• o. ••.. 0 • • • • • •• . 15 6 Adult Demodex folliculorum Isolated from Eyelash Follicle and Submerged in Peanut Oi 1 • • • • • • •••• • • • 16 7 Wormlike Extrusions Forced Out of Sebaceous Follicles of the Face By Squeezing • 17 8 Epi1ated Eyelash Showing Numerous Mites Caught Wi th Capi tulums Buried Wi thin Root Tissue Near Base of Lash • • •• 27. 9 View of Eyelid Margin Showing Mites Partially EmerOging Around a Lash After Swabbing With Ether • • • 0 • • 28 viii FIGURE PAGE 10 Comparison of the Ostia of Sebaceous Follicles With' the Openings of Superficial Lanugo Follicles ••• 34 11 Comparison of Deep Sebaceous Follicles .With Superficial Lanugo Follicles, and Their Corresponding Sebaceous Glands •••••••••••• •• 36 12. Epidermal Sheet Showing Two Adult Mites in 'Infundibulum of a Sebaceous Follicle ••••••••••• •• 37 13 Capitulum of Demodex folliculorumfrom Above •••••••••••••• 55 14 .Capitu1um of' Demodex folliculorum from Below •••• •••••••••• 55 INTRODUCTION Mi tes comprise a large a..rld important group of Arthro­ pods, although they are not well known outside of the scien·.. tifle world. Despite their obscure size, these Arachnids of the order Acarina ar~- ubiquitous animals and Acarolo- gists estimate the nwnber of species to be at least one million. They have been found living on Mt. Everest, in hot water springs, on the walls 'of caves washed by seawater and some in the depths of deep fresh'lrater wells. ..A. handful of fertile soil contains a.n average of five dIfferent forms (Bal{er and Wharton, 1952). Interest in these tiny creatures may be enhanced by knowing the nearest location of a repre- sentative of the mites -- most likely on the end of the nose or in the eyelash follicles of the reader. Mites may be free-livingj sa.prophytic, or parasitic on plants and ani­ mals, as practically all lIving things serve as hosts~ Some mammals may have as many as five different mIte forms as =- p2,rasi tes on the same anima!. Man is no exception and has been. plagued by mi tes since the beginning of record(~d his- tory. There are fIve main groups <?r fami 1i es whi ch cormnQn ly infest man with varied consequences.