following a fracture and application of plaster of Parisor fiberglass cast. To our knowledge, our patients represent the youngest three reported in the literature.
LOCALIZED ACQUIRED HYPERTRICHOSIS ASSOCIATED WITH FRACTURE AND CAST APPLICATION Alexander K.C. Leung, MBBS, PhD, FRCPC, FAAP, MRCP(UK), MRCP(I), DCH (Lond), DCH(l) and Gerhard N. Kiefer, MD, FRCSC Calgary, Alberta, Canada
Three children who developed localized hypertrichosis following a fracture and cast application are described. We postulate that cutaneous hyperemia may be responsible for the hypertrichosis. Hair growth is a complex process that requires a rich supply of oxygen and nutrients provided by the capillaries that supply the active base of the hair. ' Cutaneous hyperemia resulting from infection or trauma may result in the growth of long and coarse hair at the affected sites. The sudden appearance of excessive hair growth in a localized body area following a fracture or cast application has rarely been reported. A perusal of the literature reveals only four documented cases.2-4 We describe three children who developed localized hypertrichosis following a fracture and application of plaster of Paris or fiberglass cast. To our knowledge, our patients represent the youngest three reported in the literature.
CASE REPORTS Case 1 A 5-year-old girl was seen because of new hair growth on the left leg. Three months prior to this, she had sustained a fall with resultant fracture to the left tibia (Figure 1). She was treated with an above knee plaster of Paris cast. When the cast was removed 11 weeks later, a localized area of increased hair growth was noted where the cast had been. On examination dark, coarse, long hair was noted on the left leg; the hair growth was particularly profuse near the knee (Figure 2). The hair differed in both length and texture from that of the right leg. There was slight wasting in the gastrocnemius and quadricep muscles in the lower left limb. The child also had a limping gait. The rest of the physical examination, in particular the neurologic examination, was unremarkable. Physiotherapy was started and exercise encouraged. When seen again three months later, her gait was normal and the wasting in the gastrocnemius and quadricep muscles was no longer noted. Also, there was complete and spontaneous resolution of the hypertrichosis in the left leg with resumption of normal hair growth.
Case 2 From the Departments of Pediatrics and Orthopedic Surgery, University of Calgary, Calgary, Alberta, Canada. Requests for reprints should be addressed to Dr. Alexander K.C. Leung, Alberta Children's Hospital, 1820 Richmond Road, SW, Calgary, Alberta, Canada T2T 5C7.
A 3V/2-year-old boy presented with new hair growth over the entire right thigh and leg following nine weeks of immobilization in a 1V2 hip spica cast composed of fiberglass. The region of hair growth did not involve the contralateral thigh or leg.
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'. 7
*
;
Figure 2. Hypertrichosis seen on the left leg where a plaster of Paris cast had been applied.
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physical examination was unremarkable. Complete spontaneous resolution of hypertrichosis in the right thigh and leg was noted six months after cast removal.
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Case 3
Figure 1. Spiral fracture of the left tibia with minimal posterior displacement of the distal fracture fragment.
A 7-year-old boy with Legg-Calve-Perthes disease of the right hip was treated in Petrie cast to provide containment of the hip. Following six months of serial cast treatment to contain the hip, there was significant bilateral localized hair growth involving both the thigh and leg. Physical examination was remarkable for profuse, dark, coarse, long hair on the lower limbs. The hair growth did not differ between the right and left lower limbs but was significantly abnormal when compared with the upper limbs. The hair growth resolved completely and spontaneously nine months after cast removal.
DISCUSSION Physical examination was remarkable for long, coarse, dark hair, which was profuse over the thigh as well as the leg. The hair again differed both in texture and length from the contralateral limb. Associated muscle wasting
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Hypertrichosis refers to increased vellus hair and is unrelated to androgen excess. This is in contrast to hirsutism, which is defined as excessive male-pattern hair growth with excessive coarse hair on areas of the body that are relatively sensitive to androgens and where
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normally there is very little hair in the temale.5 Hirsutism usually results from an excess of androgens. Generalized hypertrichosis may be hereditary or it may be caused by starvation or medications such as phenytoin diazoxide." Localized hypertrichosis has been reported to develop around chickenpox scars] at the sites of insect bites,8 at the periphery of burned skin,9 and in the leg after radical inguinal lymphadenectomy. "' It also has been described following topical use of hydrocortisone5 and in mentally retarded patients who repeatedly bite or scratch their hands or arms. In 1980, Pick described a 12-year-old boy who developed an effusion of the right knee following a tall.2 A plaster of Paris cast was applied. When the cast was removed six weeks later, a prominent focal patch of hair was noted over the region of the patellar tendon. The hairy patch spontaneously resolved two months after the cast was removed. In 1983, Bergen reported a 31-yearold woman who had a Colles' fracture following a fall on a cement floor.3 She was treated with a circular plaster cast for seven weeks. On removal of the cast, a localized area of hair growth was noted where the plaster had been. When she was seen again a month later, the hypertrichosis was still persistent. In 1986, Harper reported two young females, 22 and 23 years of age respectively, who had hypertrichosis of the upper extremities associated with closed fractures.4 A splint was applied and maintained for 6 to 12 weeks. The hypertrichosis resolved over approximately six months. We report three children with localized hypertrichosis following fractures and plaster application. One of the children had a fiberglass cast-a complication not previously reported. Hypertrichosis is known to arise following chronic irritation, friction, or inflammation. Heat and cutaneous hyperemia are acknowledged by dermatologists as definite stimulants of the hair follicle.'2 Although regional blood flow to a long bone is increased following a fracture, cutaneous hyperemia is definitely a transient phenomenon and may be responsible tor the transient hypertrichosis. However, at present no histological stud-
ies have been done to confirm this. In the past, hormonal response to the immobilization has been suggested.3 Because this condition is transitory, reaction hormonal studies to date have not been confirmatory. Suggestions that hypertrichosis may be related to reflex sympathetic dystrophy'-3 is also not substantiated in the orthopedic literature. Of all the cases reported so far, only one patient had persistence of the hypertrichosis. In the patient described by Bergen,3 the persistence of hypertrichosis may be due to insufficient follow-up. Certainly all physicians should be aware of the benign and transient nature ot hypertrichosis as it relates to cast immobilization for any condition. Because of its transient nature, aggressive investigations are definitely not indicated. Literature Cited 1. Montagna W, Ellis R: The vascularity and innervation of human follicles, in Montagna W, Ellis R (eds): The Biology of Hair Growth. New York, Academic Press, 1985. 2. Pick RY: Focal hair growth under plaster-of-Paris cast. NY State J Med 1980; 80:1726. 3. Bergen D: Localised hirsutism following Colles' fracture. Can Med Assoc J 1983; 128:368. 4. Harper MC: Localised acquired hypertrichosis associated with fractures of the arm in young females. A report of two cases. Orthopedics 1986; 9:73-74. 5. Leung AK: Hypertrichosis associated with topical hydrocortisone. HK J Pediatr 1986; 1:11-13. 6. Braithwaite SS, Jabamoni R: Hirsutism. Arch Dermatol 1983; 119:279-284. 7. Naveh Y, Friedman A: Transient circumscribed hypertrichosis following chickenpox. Pediatrics 1972; 50:487-488. 8. Tisocco LA, DelCampo DV, Bennin B, et al: Acquired localised hypertrichosis. Arch Dermatol 1981; 117:127-128. 9. Shafir R, Tsur H: Local hirsutism at the periphery of burned skin. Br J Plastic Surg 1979; 32:93. 10. Finck SJ, Cochran AJ, Vitek CR, et al: Localized hirsutism after radical inguinal lymphadenectomy. N Engl J Med 1981; pp 305-958. 11. Ressmann AC, Butterworth T: Localized acquired hypertrichosis (as result of biting in mentally deficient). Arch Dermatol Syph 1952; 65:458-463. 12. Munro DD, Darley CR: Hair, in Fitzpatrick TB, Eisen AZ, Wolff K, et al (eds): Dermatology in General Medicine. New York, McGraw-Hill Book Company, 1979, pp 395-418. 13. Nielson JS: Localised hirsutism following Colles fracture. Can Med Assoc J 1983; 129:229.
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