as the anterior pituitary gland and the zona reticu-laris of the adrenal cortex, showed some individu-ally dying (apoptotic) cells. An exhaustive grossand microscopic study of the brain failed to revealany abnormal findings. Two postmortem bloodsamples yielded colchicine concentrations of 0.3and 0.4 ,umol/L.

Comments

Colchicine mainly binds to tubulin and pre-vents polymerization of the latter into micro-tubules.2 Microtubules are essential for spindleformation, a process necessary for chromosomalseparation during metaphase. Therefore, colchicineaffects rapidly dividing cells, most notably those ofthe bone marrow and gastrointestinal mucosa.

Colchicine is readily absorbed, peak serumlevels being reached 30 to 120 minutes afteringestion.2 Its half-life is about 20 minutes.3 Thereis a large volume of distribution, equal to three orfour times the total amount of body water, becauseof rapid entry into and extensive binding of colchi-cine to cells in the intestine, kidney, spleen andliver. Metabolism is partially achieved throughdeacetylation in the liver. About 16% to 40% ofcolchicine's metabolites are excreted into the bile,urine and feces within 48 hours of ingestion.4

Bismuth and associates,5 reviewing a largeseries of cases, showed that colchicine doses higherthan 0.8 mg/kg always caused death within 72

hours. The patient we have described ingestedabout 9.5 mg/kg. The findings at autopsy weretypical for colchicine intoxication.6

Treatment is complicated by colchicine's shorthalf-life and its ability to bind to tissues; thus,hemodialysis and exchange transfusions are use-less.4 Emptying of the stomach may prevent death.Because the onset of symptoms is possibly delayed2 to 12 hours, the patient should be monitoredclosely for at least 12 hours after ingestion. How-ever, death is usually multifactorial and inevitable.

This work was supported by a grant from the Nelson A.Hyland Foundation, Toronto.

References

1. Hill RN, Spragg RG, Weldel M et al: Adult respiratorydistress syndrome associated with colchicine intoxication.Ann Intern Med 1975; 83: 523-524

2. Wallace SL, Ertel NH: Plasma levels of colchicine after oraladministration of a single oral dose. Metabolism 1973; 22:749-753

3. Wallace SL, Omokoku B, Ertel NH: Colchicine plasma levels:implications as to pharmacology and mechanism of action.Am J Med 1970; 48: 443-448

4. Wallace SL: Colchicine. Semin Arthritis Rheum 1974; 3:369-381

5. Bismuth C, Gaultier M, Conso F: Aplastic medullaire apresintoxication aigue a la colchicine. Nouv Presse Med 1977; 6:1625-1629

6. Hoang C, Laverge A, Bismuth C et al: Visceral histologiclesions of lethal acute colchicine intoxications: report of 12cases. Ann Pathol 1982; 2: 229-237

Widespread dermatitis after topicaltreatment of chronic leg ulcersand stasis dermatitisDaniel J. Hogan, MD, FRCPC

C hronic leg ulcers are common, especiallyamong elderly people.' Although no effec-tive topical treatment is available,2 a variety

of topical medications are used to treat this condi-tion as well as stasis dermatitis (Table 3-9). Medica-tions applied to areas of chronic ulceration and

Dr. Hogan is an associate professor of medicine at the Universi-ty of Saskatchewan, Saskatoon.

Reprint requests to: Dr. Daniel J. Hogan, Section of Dermatolo-gy, Department of Medicine, University of Saskatchewan,Saskatoon, Sask. S7N OXO

stasis dermatitis are the most common cause ofallergic contact dermatitis of the legs,3 a conditionthat may spread to distant body sites - the "id"reaction. I describe two cases in which allergiccontact dermatitis arose from two creams thatrarely sensitize.

Case reports

Case 1

A 33-year-old man had chronic stasis dermati-tis and recurrent ulceration of the medial aspect of

336 CMAJ, VOL. 138, FEBRUARY 15, 1988

his right leg after a severe injury. He treated theulceration with 2% fusidic acid cream. When anacute skin eruption developed in association withpapular dermatitis of the arms, upper body andface he was advised to stop using the fusidic acidand to apply 0.1% amcinonide cream twice dailyto the affected areas. The dermatitis cleared in 2weeks, and the leg ulcer healed spontaneously in 3weeks.

Patch tests were performed with agents in theEuropean standard tray, as well as with derma-tologic base cream, hydrocortisone-carbamidecream, and 2% fusidic acid in cream and inpetrolatum. The sites were inspected at 48 and 96hours. Strong reactions to 2% fusidic acid in bothbases, 20% neomycin in petrolatum and woolalcohols were observed at both inspections.

Case 2

After 3 years of stasis dermatitis involving theright ankle a 66-year-old woman began treatmentwith jelly from an aloe vera plant. A moderatelyerythematous, scaly, papular eruption developedin the "V" of her neck and on her arms and rightankle. In addition, prominent varicose veins wereseen in the right lower leg (Fig. 1). She was

Table I - Topical medications reported to causeallergic contact dermatitisor stasis dermatitis3-9

Anti-infective agentsBacitracinBenzoyl peroxideBismuth tribromophenolBrilliant greenCephalexin monohydrateChloramphenicolChlorhexidineChlorquinaldolChlortetracycline

hydrochlorideErythromycinFramycetin sulfateFusidic acidGentamicin sulfateGentian violet*GramicidinHexachlorophenelodochlorhydroxyquinNeomycin sulfateN itrofurazoneNystatinPolymyxin B sulfateStreptomycin sulfateTetracycline

Anti-inflammatory agentsAloe veraBufexamacCoal tarCorticosteroidslchthammolWood tar

in patients with leg ulcers

Topical anestheticsAntihistaminesBenzocaineCrotamitonLidocaine hydrochloride

Topical basesCetyl alcoholEthylenediamineLanolinOlive oilPetrolatumPropylene glycolStearyl alcoholVitamin EWool alcohols

PreservativesChloroacetamideChlorocresolDichlorophenFormaldehydeImidazolidinyl ureaThimerosal*ParabensQuaternary ammonium

compoundsQuaternium 15Sorbic acid

OthersBenzoinMercaptobenzothiazolePerfumesRosin

*Anaphylaxis also reported.

advised to stop using the jelly and to apply 0.1%amcinonide cream twice daily for 2 weeks to theaffected areas. Her dermatitis responded well totreatment.

Patch tests were performed with agents in theAmerican Academy of Dermatology standardscreening set, as well as with aloe vera jelly, 5%crude coal tar extract in petrolatum, 1% hydrocorti-sone in petrolatum and 0.05% clobetasone17-butyrate cream. Strong reactions to formalde-hyde, quaternium 15 and aloe vera jelly wereobserved at 48 and 96 hours.

Discussion

Topical fusidic acid preparations became avail-able in Canada in 1984, but their use in Saskatche-wan was limited until 1986, when they wereincluded in the formulary of the SaskatchewanPrescription Drug Plan.10 Allergic contact dermati-tis from such preparations is rare,11 even though 19cases of sensitization have been reported.4'5'12"13Ritchie'4 prescribed fusidic acid topically for anestimated 12 000 patients over 9 years without anyevidence of adverse reactions. Of the 20 reportedcases of allergic contact dermatitis from topicalfusidic acid 15 occurred in patients with leg ulcers

Fig. 1 - Allergic contact dermatitis on right ankle ofwoman after application of aloe vera jelly for stasisdermatitis. Note varicose veins.

CMAJ, VOL. 138, FEBRUARY 15, 1988 337

or stasis dermatitis; 1 case was so severe thatsystemic corticosteroid therapy was required."3

Aloe vera preparations are widely used inself-medication.3 They are considered to be raresensitizers and have been advocated for the treat-ment of leg ulcers and stasis dermatitis.3 Therehave been four cases of allergic contact dermatitisdue to aloe vera described in the English-languageliterature,15",6 but this is the first one in which aloevera was used to treat stasis dermatitis.

In the cases I have reported, the dermatitisspread to sites remote from the site of applicationof the sensitizing medication. This id reaction incases of stasis dermatitis frequently involves theforearms, sides, trunk, face and neck in a symmet-ric pattern.'7 In some studies more than one-thirdof patients with stasis dermatitis had generalized idreactions;'7 this proportion reflects the chronicnature of stasis dermatitis, the large number oftopical medications used for its treatment (Table I)and the lack of referral to dermatologists unless anexacerbation occurs. Most patients with leg ulcersare treated on an outpatient basis by generalpractitioners.' The spread of dermatitis to remotesites has been ascribed to autosensitization, butthere is little experimental proof of this.'8

The development of allergic contact dermatitisfrom topical medications is the most importantcause of secondary dissemination of dermatitis.'7"9Widespread dermatitis may be the only sign ofallergic contact dermatitis in cases of leg ulcers andstasis dermatitis,20 especially when creams andointments are used that contain potent cortico-steroids capable of suppressing the local but notdistant reactions.20 However, a local flare-up ofstasis dermatitis generally precedes the spread ofdermatitis to other areas.

About half of the patients with leg ulcers orstasis dermatitis are allergic to one or more topicalmedications,'9 reactions to neomycin, lanolin andparabens being particularly common among thosewith stasis dermatitis.3 One of the patients I havedescribed was allergic to neomycin. Approximately30% of patients with leg ulcers will becomeallergic to neomycin.3 Lanolin and paraben preser-vatives rarely cause reactions, except when theyare applied to sites of leg ulceration or stasisdermatitis.3 One of the patients described in thispaper was also allergic to quatemium 15, a widelyused formaldehyde-releasing preservative; manypatients allergic to quaternium 15 are also allergicto formaldehyde.3

Allergic contact dermatitis from medicationsused for leg ulcers and stasis dermatitis is asignificant health problem, especially among theelderly. Patients with exacerbated stasis dermatitisor id reactions should undergo patch testing withthe use of a standard set of contact allergens aswell as the suspected medications. Relapses oflocal or generalized dermatitis may occur if thesecondary allergic contact dermatitis is not identi-fied and the patient continues to use the medica-tion. It is difficult to remove the allergens from a

patient's environment, because lanolin and preser-vatives are ubiquitous in creams. In addition,people allergic to neomycin may have severegeneralized dermatitis when they are exposed tomedications for which immunologic cross-reactionswith neomycin occur; these include gentamicinand tobramycin.3 Generalized dermatitis can beexpected to develop in people sensitized to fusidicacid applied topically who are treated with fusidicacid systemically.

The release of new topical medications for thetreatment of leg ulcers or stasis dermatitis oftenleads to the documentation of new causes ofallergic contact dermatitis. Since no topical treat-ment has been proven effective in accelerating thehealing of chronic leg ulcers in an adequatedouble-blind study, sensitizing medications, es-pecially those that are used systemically or thatcross-react with systemic medications, should beavoided.

References

1. Callam MJ, Ruckley CV, Harper DR et al: Chronic ulcer-ation of the leg: extent of the problem and provision ofcare. Br Med J 1985; 290: 1855-1856

2. Diagnosis and treatment of venous ulceration. Lancet 1982;2: 247-248

3. Fisher AA: Contact Dermatitis, Lea & Febiger, Philadelphia,1986: 92

4. Cronin E: Contact Dermatitis, Churchill, Edinburgh, 1980:193-278

5. Shehade SA, Foulds IS: Allergic contact dermatitis tobrilliant green. Contact Dermatitis 1986; 14: 186-187

6. Andersen KE, Maibach HI: Allergic reactions to drugs usedtopically. Clin Toxicol 1980; 16: 415-465

7. Milligan A, Douglas WS: Contact dermatitis to cephalexin.Contact Dermatitis 1986; 15: 91

8. Lombardi P, Campolmo P, Spallanzani P et al: Delayedhypersensitivity to erythromycin. Contact Dermatitis 1982;8: 416

9. Wereide K, Thune P, Hanstad I: Contact allergy toXeroform in leg ulcer patients. Contact Dermatitis 1983; 9:525-526

10. Saskatchewan Formulary Committee: Formzulary, Saskatch-ewan Dept of Health, Regina, July 1986: 118

11. Krogh CME (ed): Compendium of Pharmaceuticals andSpecialties, Canadian Pharmaceutical Assoc, Ottawa, 1987:340

12. DeGroot AC: Contact allergy to sodium fusidate. ContactDermatitis 1982; 8: 429

13. Romaguera C, Grimalt F: Contact dermatitis to sodiumfusidate. Contact Dermatitis 1985; 12: 176-177

14. Ritchie IC: Antibiotic treatment of soft tissue infections [C].Lancet 1973; 1: 544

15. Shoji A: Contact dermatitis in Aloe arborescens. ContactDermatitis 1982; 8: 164-167

16. Nakamura T, Kotajima S: Contact dermatitis from Aloeaborescens. Contact Dermatitis 1984; 11: 51

17. Stoltze R: Dermatitis medicamentosa in eczema of the leg.Acta Derm Venereol (Stockh) 1966; 46: 54-64

18. Parish WE, Rook AJ, Champion RH: A study of auto-aller-gy in generalized eczema. BrJ Dermatol 1965; 77: 478-526

19. Burton DC, Rook A, Wilkinson DS: Eczema, lichen simplex,erythroderma and prurigo. In Rook A, Wilkinson DS,Ebling FJG et al (eds): Textbook of Dermatology, Blackwell,Oxford, 1986: 399-400

20. Wilkinson JD, Rycroft RDG: Dermatitis from applied medi-caments. Ibid: 491-494

338 CMAJ, VOL. 138, FEBRUARY 15, 1988 For prescribing-information see page 362