Major M. P. Vora, M.B.B.S., D.V.D.,

Hon. Senior Venereologist, St. George’s Hospital, Bombay

The Antiseptic

A Monthly Journal of Medicine & Surgery

Vol.54, No. 2 of February 1957

Pages: 117-124


C hancroid is an autoinoculable infectious disease characterized by painful ulceration usually over the genital region and often accompanied by suppurative regional adenopathy. It is usually contracted through sexual contact and the casual organism is haemophillus ducreyi. The disease has been recognised as an entity for centuries and has many synonyms such as ‘ulcus molle cutis’, Ducrey’s infection’ and ‘soft chancre’.


Ducrey (1869) described Haemophillus ducreyi the causative organism. Nicolas (1899) reproduced the disease experimentally in monkeys. Koch’s postulates were put to the proof by Greenblatt and Sanderson (1937).


Chancroid has a world-wide distribution. Under unusual conditions such as war or mass-migration, it spreads widely and rapidly. It occurs much more commonly in men; so also is inguinal adenopathy more common in men than in women, probably due to the anatomical difference in the site of the primary lesion and in the drainage of lymphatics. Bruck isolated H.ducreyi from the urogenital tract of healthy women indicating that women may be carriers of the organism, a fact which may explain the cause of the low incidence of chancroid in women.


Clinically chancroid gives rise to a painful ulcer or ulcers at the site of inoculation of the germs. Being generally of venereal origin the lesion is usually on the genitalia. The incubation period varies from 1 to 3 days and its early appearance is often attributed to trauma such as a crack or an abrasion during sexual intercourse. Initially the lesion is a small crack, abrasion or an ulcer on an erythematous base. As the chancroid in creases in size it becomes somewhat irregular in outline the base is soft and covered with a purulent exudate; the borders are soft and undermined, red at the periphery and yellowish at the centre. The lack of infiltration and induration has led to the term “soft chancre”. It is always painful. Its autoinoculable nature leads to a multiplicity of lesions which appear on areas in direct opposition.


The Ducreyi bacillus seems to have a special predilection for the skin. In the male the lesion is often found on the prepuce, at the sulcus or frenum. Occasionally it may be intraurethral. In women it is found on the labia majora, labia minora, fourchette or clitoris. Involvement of the anus by direct extension is common in women. At this site it appears as a fissure surrounded by hypertrophic vegetations and is often mistaken for warts or haemorrhoids. Lesions on the prepuce very often show oedema and give rise to secondary phimosis. Extragenital lesions are not unknown. The chancroidal ulcer may vary in size and shape according to its location, pathogenicity of the germs, resistance of the individual, duration of the lesion and hygienic habits of the person. A fresh lesion is usually small and single while older lesions are invariably multiple, large and secondarily infected.


The clinical varieties are:- (1) The small uncomplicated ulcer met with in persons of clean habits; (2) the papular type - the lesion is elevated, crusted and often associated with a warty growth, usually seen in women, and (3) phagedenic chancroid - a rapidly destructive lesion spreading extensively not only on the genitals but also on the thighs and abdomen, Vincent’s bacillus or Fuso-spirochaetes being often seen in smears from the lesion. In the pre-sulphanilamide era, this type of lesion used to be extremely resistant to local therapy and to cause vast destruction of essential organs.


Inguinal adenitis - is often a common feature in a fairly large number of patients especially of unclean habits, and is commoner in men than in women. It is precipitated by unclean habits, hard work and lack of rest. Extra-genital lesions are generally not followed by regional adenopathy. The bubo develops 1 to 2 weeks after the appearance of the ulcer. It may be prevented by the administration of sulpha drugs very early in the course of the disease. Adenitis usually occurs on the side of a chancroid or it may be bilateral. Lymph glands are enlarged and tender; periadenitis follows, and the overlying skin becomes red. In a few days the glands becomes soft and fluctuating and the skin on them becomes thin, shriveled; the buboes then burst, and discharge a good amount of pus leaving a sinus. Inoculation of the skin around the sinus is quite possible and may cause the disease to spread. If not properly treated the ulceration may last for a few months, causing extensive destruction of the tissues.

The most important symptom in chancroid is pain both at the site of the ulcer and in the adenopathy. The skin over the bubo does not become thickened and oedematous or show furrows as in the adenopathy of lymphogranuloma venereum.


Chancroid may be contracted simultaneously with other venereal diseases. It may co-exist with syphilis, gonorrhoea, lymphogranuloma venereum or granuloma inguinale. Such combinations are not unusual. The clinical picture is usually mixed and bizarre depending on the character of each disease.


Systemic changes are very mild. Where buboes and extensive ulceration are present, fever, malaise and aching may be noticed. There is however, rapid response to specific therapy; the fever subsides, the pain becomes less, the discharges decrease and healing starts in 2 to 3 days. Glands subside rapidly if there is no softening and fluctuation. One attack does not confer immunity, against subsequent infections if exposed to H.ducreyi.


Clinically chancroid should always be suspected when there is a painful, purulent ulcer of short incubation, with an acute and painful adenopathy. The diagnosis must not be made on the clinical appearance alone but must be confirmed by laboratory examinations and all procedures for the exclusion of syphilis must be carried out before a diagnosis of chancroid is made.


Laboratory diagnosis:-


The diagnosis of chancroid can be arrived at by different laboratory tests all of which have their limitations. No one method can be applied in all cases and the procedure suitable for each case must be selected depending on the duration, and type of the lesion. For reasons of expediency one is often tempted to make a diagnosis by exclusion only i.e. considering as chancroid a genital lesion in which a dark-field examination is negative for T. pallida and which responds to sulphanilamide therapy; but such temptation must be avoided as far ass possible. It would not right to call a genital lesion a chancroid simply because the dark-field examination is negative for T. pallida. It is equally important to exclude other venereal diseases and correlate the findings with clinical and laboratory investigations. The judicious use of appropriate procedures in the diagnosis of chancroid will rule out other venereal diseases.


The diagnostic procedures vary in their accuracy, techniques and availability. Some are direct methods such as the demonstration of the causative organism in smears and cultures, study of tissue reaction, auto-inoculation, histologic changes and intradermal test with Ducrey vaccine to detect specific immunologic changes, while other methods used in the diagnosis of other venereal diseases are indirect and are usually negative in chancroid.


Smears for H.ducreyi :- The actual demonstration of H.ducreyi in a smear from the ulcer is definite proof of the disease. Great care must be taken in the selection of the site, collection of material and preparation of smears.

The lesion should be thoroughly cleaned with saline and a smear made with a short thick platinum wire. The overhanging edge of the ulcer or undermined border of the ulcer especially advancing, is the best site for taking material for smears. The slides are prepared, dried and fixed by heat; Unna-Peppenheim stain is recommended. Wright’s or Geimsa’s stain may be used for staining instead.


The Ducreyi bacillus is gram-negative, short, thick, with rounded ends which often stain deeply giving rise to a “safety-pin” appearance. It may be intra- or extra-cellular. Its long chains often in parallel lines suggest the typical appearance of “shoals of fish”. The smears from advancing borders of an ulcer show parallel rows of bacilli while the smears from cultures give long chains. Lesions which are more than 3 and less than 8 or 10 days’ duration, are best for obtaining positive smears. Older lesions get secondarily infected with other organisms> in experienced hands this method has yielded successful results in 65 to 88 per cent of cases. In rapidly destructive lesions, super-imposition of fuso-spirochaetes should be suspected and ascertained by examining smears.


Ito-Reensteirna test or Ducreyi vaccine skin test: - The value of this skin test in diagnosis is debatable. The test may be negative in the very early stage of the disease and become positive after some time, to remain so thereafter. The Ducreyi vaccine (Lederle Laboratory) is available in 0.2 cc. or 5 cc. vials for two or fifty tests. The tube is well shaken and the required material i.e., 0.1 cc. is drawn in a tuberculin syringe and injected intradermally on the flexor aspect of the forearm. Control is not necessary. In a positive case, an erythematous papule from 7 to 12 mm. in diameter is noticed at the site within 48 hours. The test is then reported positive. In a negative case there is minimal reaction which fades away rapidly. The test is usually positive in the first or second week of the infection but occasionally after six weeks. It is almost invariably positive after the appearance of adenopathy.


Evaluation of the test : - A positive reaction indicates that the patient is infected with H.ducreyi. It does not necessarily mean that the lesion actually under observation is of a chancroidal nature as the reaction will be positive even in patients who had had chancroid years ago. The interpretation of the test is conclusive only in cases with a negative history of previous venereal disease. The test is of definite value when a negative reaction found at the onset of the disease is followed by a positive one when the test is repeated two weeks later. A negative test would indicate that the patient has not been infected with H.ducreyi or that if the infection has occurred; it is so recent that the patient has not developed sensitivity to the vaccine. In the latter case, the test should be repeated after 1 to 2 weeks. In some cases of chancroid where treatment is instituted immediately after the onset of infection, sensitivity does not develop and the test is often negative.


Auto-inoculation of the chancroid is one of the oldest diagnostic methods used in venereal diseases. An inoculation with material from the suspected lesion is made in the same patient presenting the disease. A drop of pus from the ulcer is placed on the normal skin of the patient, and scarifications as in small-pox vaccination, are made through the drop with a sterile needle, avoiding bleeding. The area is then covered with sterile dressing. If positive, several small pustules will appear in 24 hours on the spot. In a couple of days they ulcerate and form minute chancroids which may become large and painful. H.ducreyi may be demonstrated in the smears made from these lesions. Sulpha-drugs are very effective, as they cure both the original lesion and the auto-inoculation. Local treatment consists of keeping the part clean and well-drained. Auto-inoculation is not meant for general use and should not be practiced as a routine. This method was found to be successful in about 80 percent of cases.


Culture of H.ducreyi: - Is a difficult procedure requiring special media such as defibrinated rabbit’s blood or tryptine phosphate medium with fresh rabbit’s blood. The colonies are characteristic in appearance and the organisms show a definite pattern in their spread. They may be in clumps or chains according as the medium used is solid or liquid. When the lesion is contaminated with other bacteria, the culture test is likely to fail in about 75 percent of cases.


Microscopic examination of the tissue from the ulcer is of value in the diagnosis of chancroid. The histologic changes occurring in the lesion have a distinct pattern and permit a reasonably certain diagnosis in nearly every case. This method could however seldom be used as a routine but it is the most reliable single method of diagnosis. A piece of tissue 3 mm. in diameter is removed from the ulcer with a Gaylor’s forceps, processed and examined. The ulcer shows three distinct zones. The surface zone made up of polymorphonuclear leucocytes fibrin, red blood cells and necrotic tissue in which endothelial cells in various stages of proliferation predominate over other cellular components. Newly formed numerous blood vessels show palisading with occasional degeneration of the walls and thrombosis. The deepest zone is made up of a dense infiltration by plasma cells and lymphocytes. H.ducreyi may be occasionally seen in the tissue. In cases of chronic chancroidal ulceration, this method is of special value in ruling out malignancy and in confirming Ducrey’s infection.


There are other methods i.e. indirect ones which must invariably be employed to help in the total evaluation of clinical and laboratory findings. Repeated negative dark-field examinations eliminate the possibility of syphilitic infection and help in the diagnosis of chancroid. Serological tests for syphilis are negative in these cases unless there is double infection. The treponema immobilization test is negative. Frei test for lymphogranuloma venereum is also negative.


From the point of view of the general practitioner who has often to deal with these patients, the diagnostic procedures ought to be the most easy and the most practical. Of the direct methods, smears from the ulcer for H.ducreyi and Ito-Reensteirna test or Ducrey skin-test may be considered feasible office procedures; others are not for routine use but may have to be used occasionally in the diagnosis and management of venereal diseases. Among the indirect methods which help to rule out other venereal diseases, the dark-field examination of T. pallidum and the serologic test for syphilis must always be performed. Frei Test for L.V. may have to be undertaken where inguinal adenopathy is suggestive of L.V.

The prognosis in cases of chancroid is always good and a complete and rapid cure is possible in every case when proper treatment is instituted early. One attack does not confer immunity, and reinfection is quite possible. The introduction of sulphanilamides and antibiotics in therapy has greatly shortened the course of the disease, prevented painful adenopathy, phagedenic conditions and helped in the prevention of infection.


Treatment of chancroid

P rophylaxis: - Chancroid is preventable. Immediately after intercourse the patient should wash his penis thoroughly with soap and water and then with some antiseptic lotion. If applied within an hour, a 10% aqueous solution of ephiran chloride and 2% solution of prophyline glycol are reported to afford complete protection. Sulphathiozole or sulphadiazine may be used orally as a prophylactic. Antibiotics - streptomycin, aureomycin and chloramphenicol are all effective for systemic prophylaxis against chancroidal infection.


L ocal Treatment: - With the advent of the sulphanilamides, the local treatment of chancroid has altered greatly. Normal saline dressing with good drainage and proper cleanings are ordinarily quite effective. Where there is oedema, hypertonic saline should be used. Surgical intervention such as dorsal slit or circumcision if considered necessary should be undertaken a couple of days after sulpha-drug therapy. Topical applications of antibiotics or antiseptics to the lesion must not be used as they are likely to interfere in the early exclusion of syphilis. If the regional lymph nodes are tender, frequent applications of dry heat, rest in bed, together with sulpha-drugs will abort bubo-formation. If there is softening and fluctuation, the bubo must not be incised but only aspirated with an 18 gauge B.D. needle and a tight bandage applied. Aspiration may have to be repeated once or twice in cases. Injections of antiseptics into the bubo are neither necessary nor advisable. A few injections of a good preparation of chancroid vaccine intravenously in gradually increasing doses at two-day-intervals, helps to bring about early resolution of the adenitis.


S ystemic treatment: - Most of the cases of chancroids can be treated in the outpatient as ambulatory. It is advisable to hospitalize those with extensive ulceration, phagedena and painful adenopathy. The administration of sulphanilamides orally is the therapy of choice, as the results are uniformly good. The average dose of 1gm. at 4 hourly intervals, four to five times a day for five days in very early cases and for 7 days in late cases with adenitis, is usually very effective. An initial dose of 1.5 to 2 g. may be given. There is no need to give the drug beyond the above limit. Sulphadiazine, sulphamerazine, Ganstrine or sulphathiozole are equally effective and do not usually cause side-effects of a severe nature; they are therefore, superior to the more recent antibiotics. The margin between the effective and the tolerated dose is quite safe. The effect of medication is often rapid and dramatic. H.ducreyi is not found in smears taken 48 hours after treatment; the pain decreases, the discharge subsides, the ulcer becomes clean and healing starts. Adenitis rarely develops after two days’ therapy. If adenitis is already present, the glands begin to subside, but if they are fairly grown in size, the resolution is slow; softening and fluctuation may follow. The use of penicillin is not recommended as it is not effective at all in uncomplicated chancroid, but it is likely to mask co-existing syphilis. Sulpha-drugs may be given with penicillin in cases where a double infection such as syphilis or fuso-spirochaetes is present. Streptomycin, dihydrostreptomycin or a combination of the two is effective in chancroidal infection but does not appear to be able to prevent the formation of buboes or their subsidence and resolution. In most cases the average daily dose is 1g. intramuscularly for about 5 days is sufficient. The oral broad-spectrum antibiotics such as aureomycin, terramycin etc. , are also effective against chancroid but they need not be preferred to the cheaper sulpha-drugs; the antibiotics may upset delicate biological functions of the digestive tract and also the intestinal bacterial flora. Further they are in no way superior to the sulpha-drugs in preventing bubo-formation or its progress to suppuration. They are indicated only when there is no response to sulphanilamide, or when sensitivity and resistance are noticed. The dosage recommended is 0.5 g. four times a day for about 5 to 10 days depending on the response.


Complicated cases : - If chancroid and early syphilis are both present, penicillin should be given along with sulpha-drugs, using a 8 to 10 days the standard dosage i.e., 4.8 mega units of procaine penicillin for the sero-negative primary stage and 6 mega units for the early sero-positive stage. If chancroid is associated with lymphogranuloma venereum, sulpha-drugs or the broad-spectrum antibiotics should be tried.


This treatment is also effective in chancroid, with granuloma inguinale (Donovanosis); when chancroid and gonorrhoea co-exist, sulphadiazine or sulphathiozole is useful. A single dose of 400,000 units of procaine penicillin fortified with 100,000 units of crystalline penicillin may be tried and the masking of syphilis kept in view. If fuso-spirochaetes are found, repository penicillin 600,000 units should be given daily for about 3 days.


Follow-up : - When the treatment is over, the patient should be kept under observation and serologic tests for syphilis carried out at stated intervals for three months.