Postgrad Med J: first published as 10.1136/pgmj.43.499.353 on 1 May 1967. Downloaded from Postgrad. med. J. (May 1967) 43, 353-358. A review of pilonidal sinus lesions and a method of treatment B. P. FLANNERY H. A. KIDD F.R.C.S. F.R.C.S.E. St Helier Hospital, Carshalton, Surrey Introduction barbers has been reported by Patey & Scarff (1946, This paper on pilonidal lesions is presented with 1948, 1955). Lesions have also been found in the the object of reviewing the disease and describing anterior perineum (Smith, 1948), axilla and a method of treatment introduced by Jacobsen umbilicus (Aird, 1952) and also in an amputation (1959). stump (Shoesmith, 1953. From a review of umbilical A pilonidal sinus is an anomalous condition, in sinuses and fistulae (Steck & Helwig, 1965) thirty- which there may be found a nidus of epithelial and eight sinuses have been histologically identified as hair cells submerged in the cutaneous tissues of the pilonidal. intergluteal cleft. These elements under certain conditions give rise to symptoms or signs. Their Aetiology presence is indicated by a number of fine circular The cause of pilonidal sinuses has during the last pits, which are aligned vertically and are of four to five decades been in doubt. For some time, variable orifice-diameter. They are usually two or two beliefs supporting a congenital theory of origin thiree in number, although larger numbers have were held: (a) remnants of the neural canal be- copyright. been described. They extend to the caudal end of came separated off and isolated, thus leading to a the anal cleft, superior to the posterior anal verge sinus tract; and (b) malfusion of the body halves beyond which they are not seen. They show no resulted in an ectodermal inclusion site. Supporters tendency to deviate from a strictly midline posi- of these theories demonstrated a space or canal tion. lying between the coccyx and skin, constant in The first clinical report of a pilonidal sinus is small embryos (Mallory, 1892) and variable in reputed to have been in 1847 (Dwight & Maloy, foetuses (Kooistra, 1942), which normally dis- 1953), but Hodge in 1880 is accepted as giving the appeared at birth. A skin dimple, at times deep http://pmj.bmj.com/ lesion its name 'pilonidal'. enough to be called the 'cisterna' of a sinus is said to be present in 150% of newly born infants. This Incidence dimple usually disappears soon afterwards, but There is no real age range, although sinuses are may persist into adult life in less than 30 of usually seen in adolescence and early adulthood. people. There seems, however, to be no direct Patients in the seventh decade have required treat- relationship between these developmental dimples ment for the first time, and Lewin (1965) has and sinus. Nor are other pilonidal anomalies such on September 25, 2021 by guest. Protected reported thirty-eight occurrences in children under as epithelial downgrowths and persistent neuren- the age of 1 year. Twenty-three of these infants teric canal remnants, or vestigial secondary sex were males and fifteen females. The incidence, glands such as the bird's preen gland, of any normally two male to one female, may vary by as aetiological significance. In the last 20 years, an much as 10: 1. This latter figure is, however, acquired cause has been widely accepted. This was exceptional, and is accounted for by the 1939-45 stimulated by the finding and reporting of Patey war years. Hardaway (1961) reported that during & Scarff (1946) of pilonidal sinuses in barbers' the years 1942-45, 77,657 soldiers of the United hands seen in the interdigital clefts. Also about States Army with pilonidal lesions were treated. this time King (1946) wrote that hairs must be A further 9000 were observed to have lesions important causative agents as the hairs found in which did not require treatment. sinuses had their roots nearest the sinus opening. The intergluteal cleft is not the sole site of Later Weale (1955) in a histological study of the these lesions as was once thought. Hodge in 1880 hairs in pilonidal sinuses suggested that as the roots reported that the removal of hairs from the skin of these hairs were deeply sited in the tissues, they of the feet was practised in those days. Pilonidal must be developmentally present in the sinus. He sinuises in the interdigital clefts of the hands of regards the barber's hand sinus as an implantation Postgrad Med J: first published as 10.1136/pgmj.43.499.353 on 1 May 1967. Downloaded from 354 B. P. Flannery and H. A. Kidd dermoid. Patey & Scarff contested this idea, lining in eight. The hairs may be found either in and offered the explanation that the cuticular the sinus or extruding from the pit mouth. surface arrangement of hair scales was such Occasionally also a hair may be seen looped over as to drive hair, root first, into the skin. About or inverted, entering a pit mouth. They lie in the same time, Brearly (1955, 1959) intro- bundles with their axes in the line of the raphe. duced a puncture and suction theory, illustrated In colour they are usually dark or brunette, with by manometric tracings of pressure variations in a barbed feel as if the normal scale arrangement the gluteal cleft area. He displayed this, introducing had been exaggerated. Ginger hairs have also a needle connected to a capacitance manometer been described and blonde hairs are seen in into the subcutaneous tissues of the intergluteal Scandinavians. cleft. He pointed out that any force withdrawing skin laterally across the buttocks puts tension on Symptomatology the fascial bands between deep fascia and skin. Most patients complain of either a sinus dis- This is enhanced by gluteal muscle contraction. It charge or of a painful swelling. This latter may also occurs with stretching of buttock skin as resolve to reappear later on after the fashion of a induced by flexing the thighs and vibrating the so-called blind boil. Sinus discharge is usually lower limbs. These movements are seen in motor- secondary to a bout of infection, and may be cycle pillion riders and drummers of dance bands. accompanied by a crop of small follicular pustules. As the result of pressure variations set up by the These may also be secondary to the sinus dis- factors mentioned above, a suction effect occurs charge, but commonly are the result of irritation and hairs tend to puncture the skin and proceed and infection produced by strapping of the zinc by suction to a deeper location carrying epithelium oxide type to which some skins are sensitive. with them. Palmer (1959) offered a theory as to Cleansing with suitable agents, methylated spirit how hairs gain entry to a sinus. At puberty there is or cetavlon, etc., and avoidance of strapping heals a natural enlargement of the buttock and gluteal the condition. The discharge from a sinus fluctuates muscles. He believes that, at this time, there is a and to a degree is dependent on the quantity of copyright. lateral stretch directed away from the midline on infected epithelium contained within the tracts. each side of the raphe. As a result of these forces, Not infrequently the sinus dries up and may stay a spread or stretching of normal skin orifices healed without the need for further treatment. occurs, thereby permitting the entrance and pack- More usually it recurs, and it seems that chemo- ing of hair. therapy has no effect on the closure rates of these sinuses. More rarely patients will complain of Pathology bleeding, and this is often due to scratching. At Epithelial cells and hairs form the pilonidal other times the patient complains of discomfort http://pmj.bmj.com/ sinus. There is, however, no sure evidence of the when sitting. depth to which epithelium is present in these It is perhaps salutary to remember that pilonidal lesions. Usually granulation tissue is seen to form sinuses are found by accident in patients who have the deeper aspect of the sinus tract. In some cases had no symptoms from them, and who may have epithelium does not extend beyond 1-2 mm from been totally unaware of their presence. In such the surface. It is doubtful whether this is due to cases treatment is not justified. epithelial halt or to whether there is destruction on September 25, 2021 by guest. Protected of deeper epithelium and replacement by granula- Treatment tion tissue. It is possible that if skin pitting occurs Prophylactic. There are no measures that will from muscle stretch, then the microscopic opening with certainty prevent pilonidal formation, but the of surface pits might be compensated by an incidence of recurrent infection can be lowered by epithelial downgrowth, preceding the entry, by adherence to the following hygienic measures: (a) drilling action, of hairs. Subsequent infection of hairy patients would be wise, particularly in warm epithelium and foreign body irritation of hairs and moist conditions, to shave frequently the inter- would lead to granulation tissue production. gluteal area, perhaps every 4-5 days; (b) all hairs Kooistra (1942) took multiple sections of sinuses round sinus openings to be removed, either by and found no evidence of epithelial lining in 39% shaving or scrubbing or with epilation creams; of cases. Hair follicles are of doubtful occurrence (c) careful anal toilet; (d) soap and water, or and some think they never occur. Kooistra, how- detergent cleansing of the intergluteal area with ever, reported a 9% incidence. Palmer found hairs thorough drying; (e) in certain exceptional cir- present in 50% and squamous epithelium in 30% cumstances, the avoidance of occupational hazards, of ninety-six cases.