J Cutan Pathol 2014: 41: 699–702doi: 10.1111/cup.12381John Wiley & Sons. Printed in Singapore

© 2014 John Wiley & Sons A/S.Published by John Wiley & Sons Ltd

Journal ofCutaneous Pathology

Cover Quizlet

Tee W Siah MBChB1 and Leonard Sperling MD2

Figures 1 and 2 are depicted on the journal cover.

Figure 3. Figure 4.

Your diagnosis?

Discussion follows on page 700

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The histopathologic diagnosisof post-operative alopecia

Tee W Siah MBChB1 and Leonard Sperling M.D.2

1University of British Columbia, Department of Dermatology and Skin Science, 835 West 10th Avenue, Vancouver, BC V5Z 4E82Dept. of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814

Leonard Sperling, MDDept. of Dermatology

Uniformed Services University of the Health SciencesBethesda, MD 20814

Phone: (301) 295-9802email: Leonard.sperling@usuhs.edu

Keywords: post-operative alopecia, pressure-induced alopeciaAccepted for publication July 20, 2014

Post-operative (or pressure) alopecia representsan uncommonly reported condition resultingfrom a prolonged period of head immobilizationon a firm surface. The entity was first reportedin 1960 by Abel and Lewis,1 who observed eightfemale patients presenting with discrete areas ofalopecia a few weeks after undergoing prolongedgynecological surgery. Post-operative alopeciahas been reported following prolonged stays inintensive care units and after various surgicalprocedures for cardiothoracic, gynecologicaland breast, abdominal, maxillofacial, orthodon-tic and ophthalmologic indications.2–8 Onereport documents post-operative alopecia in apatient who sustained direct blunt trauma to thescalp.9 The condition can affect both adults andchildren1 and the occiput is the most commonlyaffected site.10 Some patients experience ten-derness, swelling or crusting prior to the onsetof alopecia, but in others localized hair loss maybe the only presenting feature. The onset ofalopecia typically occurs 3 to 28 days followingsurgery9 and hair loss may be temporary orpermanent.3

To date, more than 30 cases of post-operativealopecia have been documented.11 However,only a few addressed the histopathologic fea-tures of the phenomenon1,3,4,12–15 (Table 1). Atpresent, no well-defined histopathologic criteriafor post-operative alopecia have been described

in the peer-reviewed literature. We believe thatthe microscopic findings are sufficiently distinc-tive to allow for a definitive diagnosis in mostcases.

Our patient was a 24-year-old male who devel-oped a localized area of alopecia on the vertexof the scalp following orthopedic (knee) surgerythat lasted 7 hours. He presented to a dermatolo-gist 26 days later with a well-demarcated, four byseven centimeter oval patch of alopecia involvingthe vertex of the scalp. Within the patch, shorthairs of various lengths and underlying erythemawere noted. The patient’s eyelashes, eyebrows,body hair, and nails were normal. No additionalskin lesions were noted. Photographs of the scalplesion were not obtained.

A punch biopsy of the involved occipital scalpwas performed. The submitted specimen was sec-tioned horizontally at multiple levels. The totalnumber of terminal follicles was normal, butalmost all follicles were in the catagen/telogenphases (Figs. 1 and 2). Trichomalacia was seenwith abnormal pigmented hair shafts that wereintact but irregularly shaped (Fig. 3). Vascu-lar congestion and thrombosis were present inthe peribulbar fat along with subtle lipodystro-phy; no significant inflammation was present(Fig. 4). Based on the combination of clinicaland pathologic findings, a confident diagnosis ofpost-operative alopecia could be rendered.

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Table 1. Previously published histopathologic descriptions of postoperative alopecia

Author Year Timing of biopsy Histology

Abel and Lewis1 1964 One week to 2 months followingsurgery

Obliterative vasculitis, atrophic hair follicles, moderatepanniculitis, mild perivascular lymphocytic infiltrate

Lawson et al3 1976 Immediate post-operative period Intravascular thrombosis, edema, early hair follicle necrosis andperivascular inflammation.

Wiles and Hansen13 1985 Approximately 4 weeks followingsurgery

Edema of the epidermis and papillary and reticular dermis; heavydermal infiltrate of neutrophils, lymphocytes andmacrophages.

Boyer and Vidmar14 1994 4 weeks following surgery Fibrosis and chronic inflammation within papillary andsuperficial reticular dermis; all follicles in catagen phase, withsome necrosis of individual hair bulb cells.

Hanly et al12 1999 One week following surgery Multiple catagen-phase hair follicles; no significantinflammation; apoptotic bodies in the follicular epithelium; allfollicles in the catagen-phase; no evidence of folliculardisruption or atrophy; some pigment casts within the follicularinfundibulum; no evidence of panniculitis or vasculitis; elastictissue stain showed complete preservation of the dermalelastic tissues.

Dominguez-Aunon et al4 2004 3 months after the initialpresentation

Dilated and destroyed hair follicles invaded by a neutrophilic-richcellular infiltrate; foreign-body granulomatous reaction andfibrosis; neutrophilic pustule in the stratum corneum above anaffected follicle.

Ozdemir15 2013 Approximately 2 weeks after thepresentation

Multiple anagen and telogen hair follicles without any peribulbarinflammatory infiltrate.

Fig. 1. A horizontal section at the level of the mid dermis showsthat almost all follicles are in catagen/telogen phase.

Several relatively common dermatologic condi-tions may be considered in the differential diag-nosis of post-operative alopecia. Alopecia areata(AA) should be considered because it shares withpost-operative alopecia a history of abrupt onsetof an oval, well-circumscribed patch of scalp hairloss. Also, both post-operative alopecia and AAdemonstrate the microscopic features of cata-gen/telogen shift and occasional pigment casts.However, the presence of hair miniaturization,‘nanogen’ hairs and focal peribulbar inflamma-tion would be expected in AA. Trichotillomania

Fig. 2. A high power view demonstrates follicles in catagen andtelogen phases.

must also be considered. Patients with trichotil-lomania usually present with sharply demarcatedand geometrically shaped areas of alopecia con-taining sparse hairs that appear broken off atvarying lengths. Histopathologically, a markedincrease in terminal catagen/telogen hairs andtrichomalacia can be seen. Trichotillomania dif-fers from post-operative alopecia in that there isno history of a recent operation; involvement isoften in a non-occipital location and non-oval inshape; there is microscopic evidence of follicu-lar distortion and incomplete follicular anatomy,

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including the absence of shafts and portions ofinner and outer root sheath; and the absence ofvascular and fatty changes.

Even without a clinical description, thehistopathologic changes of post-operative alope-cia are sufficiently distinctive to either suggestor confirm the diagnosis. Early in the courseof the disease, before hair loss is complete, thefollowing may be seen: intravascular congestionand thrombosis; fatty changes (lipolysis withlipophages); variable degrees of perivascularand perifollicular lymphocytic inflammation;and follicular bulbar necrosis and pigment castformation. In areas of fully-developed involve-ment, the most striking finding is the conversionof nearly all terminal follicles into catagen andtelogen phases. This synchronized conversion tocatagen/telogen has been described by severalauthors12,14–16 and is highly characteristic ofthe disorder.16 Features such as deep dermalobliterative vasculitis, atrophic follicles andpanniculitis can be found in some extremeexamples.1 At later stages of the disease, perma-nent hair loss can occur, especially centrally. Abiopsy performed at this stage will show featuresof end-stage scarring alopecia with total absenceof follicular epithelium and sebaceous glands.

The cause of the condition is thought tobe pressure-induced ischemia and localizedhypoxia of hair follicles.1,3 It has been shownthat frequent intraoperative head repositioningto prevent prolonged localized pressure maybe helpful as a preventive measure.3,11 Theprognosis is generally favorable, and completehair regrowth may occur spontaneously within

four months, although several cases of perma-nent hair loss have been reported.3 Such casesare presumably associated with more severelocal anoxia with subsequent follicular necrosis,secondary fibrosis, and scarring. Treatment isneither necessary nor possible, but patientscan be reassured that the condition is usuallyreversible and self-limited.

In summary, we posit that post-operativealopecia represents an uncommon but clinicallyand histopathologically distinctive form of hairloss occurring after prolonged immobilization.Our case shares many similarities with previ-ous reports, including vascular congestion andthrombosis, mild perifollicular inflammation,and the formation of trichomalacia and pig-ment casts. However, the most distinctive anddramatic feature seen in the first few weeksof post-operative alopecia is the synchronizedconversion of most or all terminal follicles tocatagen and telogen phase. Given the potentiallong-term outcomes of permanent hair loss andscarring, it is important for dermatopathologiststo establish the diagnosis, thereby providingeducational feedback to the dermatologist orsurgeon and preventing future mishaps.

Fig 3. Trichomalacia is seen at the level of theinfundibula with abnormal hair shafts that areintact but oddly shaped.Fig 4. Vascular congestion or thrombosis ispresent along with replacement of some fatcells by loose connective tissue. No significantinflammation is present.

References1. Abel RR, Lewis GM. Post-operative (pres-

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M. Post-operative alopecia areata: is

pressure-induced ischemia the only cause

to blame? Transplant Proc 2004; 36: 2158.

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bypass. The Journal of thoracic and cardio-

vascular surgery 1976; 71: 342.

4. Dominguez E, Eslinger MR, McCord SV.

Post-operative (pressure) alopecia: report

of a case after elective cosmetic surgery.

Anesth Analg 1999; 89: 1062.

5. Poma PA. Pressure-induced alopecia.

Report of a case after gynecologic surgery.

The Journal of reproductive medicine

1979; 22: 219.

6. Bruce IA, Simmons MA, Hampal S.‘Horseshoe-shaped’ post-operative alope-cia following lengthy head and necksurgery. J Laryngol Otol 2002; 116: 230.

7. Lypka MA, Yamashita DD, Urata MM.Post-operative alopecia following orthog-nathic surgery. J Oral Maxillofac Surg2008; 66: 1957.

8. Bhatt HK, Sharma MC, Blair NP. Pressurealopecia following vitreoretinal surgery.American journal of ophthalmology 2004;137: 191.

9. Ferran NA, Dharmarajah R. Pressurealopecia following blunt trauma. InjuryExtra 2006; 37: 200.

10. Eldred WJ. Occipital alopecia. The Jour-nal of thoracic and cardiovascular surgery1977; 73: 322.

11. Davies KE, Yesudian P. Pressure alopecia.International journal of trichology 2012; 4:64.

12. Hanly AJ, Jorda M, Badiavas E, ValenciaI, Elgart GW. Post-operative pressure-induced alopecia: report of a case anddiscussion of the role of apoptosis innon-scarring alopecia. J Cutan Pathol1999; 26: 357.

13. Wiles JC, Hansen RC. Post-operative (pres-sure) alopecia. J Am Acad Dermatol 1985;12: 195.

14. Boyer JD, Vidmar DA. Post-operativealopecia: a case report and literaturereview. Cutis; cutaneous medicine for thepractitioner 1994; 54: 321.

15. Ozdemir EE, Gulec AT. Clinical evaluationof post-operative pressure-induced alope-cia using a hand-held dermatoscope. Int JDermatol 2014; 53: e309.

16. Sperling LC, Cowper SE, Knopp ES.Post-operative (pressure-induced) alope-cia. In An atlas of hair pathology withclinical correlationsSecond ed. London:Informa Healthcare, 2012; 72.

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