Balanitis xerotica obliterans: epidemiologic distribution in an equal access health care system. (Original Article).

Background: We analyzed the incidence of balanitis xerotica obliterans (BXO) by both age and ethnicity at an equal-access health care facility.

Methods: We retrospectively reviewed discharge records from 1997 to 1999 at Brooke Army Medical Center to determine ethnicity and age of patients with BXO.

Results: Of 153,432 male patients, 108 (0.070%) had a diagnosis of BXO. The age distribution was similar over a range from 2 to 90 years, with the exception of the third decade, when the incidence almost doubled. Black and Hispanic patients had twice the incidence found in white patients (10.59, 10.67 and 5.07 per 10,000 patients, respectively).

Conclusion: At our equal-access health care facility, the incidence of BXO in black and Hispanic patients was double that in whites. This unexpected finding, in concert with the greater incidence in the third decade, may result from greater access to medical attention for these patients in the military setting. Nevertheless, further research into the origin of the disease is warranted.

Key Words: ethnic groups, genital diseases, incidence studies, males

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Balanitis xerotica obliterans (BXO) was first described in the urologic literature in 1928 by Stuhmer, (1) who reported it as a postcircumcision phenomenon. White, scaly papules generally involve the glans, prepuce, and urethral meatus, and may distort the penile architecture. Upon closer examination, white or brown horny, follicular plugs may be seen on the surface of these lesions, a feature referred to as "delling." (2) Typically, patients present with painful erections, itching, difficulty in retracting the foreskin, and loss of glanular sensation. (3) Voiding complaints may accompany meatal involvement. (3-6)

This disease must be differentiated by skin biopsy from lichen planus, erythroplasia of Queyrat and leukoplakia, as all are grossly similar. Histologically, BXO is remarkable for hyperkeratosis, a thinned epithelium, and loss of the rete pegs. (In contrast, the other conditions will show hypertrophied rete pegs.) The most dramatic characteristic of BXO is a pale-staining subepidermal layer composed of homogenized collagen and edema (Fig. 1). In later stages the papillary dermis is infiltrated with lymphocytes and plasma cells. Balanitis xerotica obliterans is now commonly regarded as synonymous histologically and clinically with male genital lichen sclerosus et atrophicus. (7)

As rare as BXO is thought to be, it remains the most common cause of acquired urethral meatal stenosis in children and adults. (4,8) The epidemiologic breakdown, however, has yet to be reported. In our retrospective epidemiologic study of 108 patients with BXO, some interesting findings are worthy of note.

Methods

We performed a retrospective computer search of the military's Standard Ambulatory Data Records for Brooke Army Medical Center at Fort Sam Houston, TX. The data were searched for patients' first date seen on an outpatient basis for treatment of BXO during the fiscal years 1997 to 1999. Records with insufficient or questionable data on BXO were reviewed individually for clarification. Patients were classified by age and ethnicity (white, black, Hispanic, and other/ unknown), and the incidences were documented. A 95% large sample confidence interval was used for analysis of all data.

Results

Of a total eligible population of 153,432 male patients, 108 had BXO diagnosed for the first time at Brooke Army Medical Center from 1997 to 1999 (an incidence of 0.070% [7.04 [+ or -] 1.33/10,000 eligible patients]). The distribution by age and ethnic background is shown in Tables 1 and 2, respectively. Results showed a relatively even distribution of BXO throughout all age groups, with one exception: the age group 21 to 30 years showed a nearly double incidence of BXO. A comparison of BXO by ethnic background reflected virtually identical incidences between black and Hispanic patients (10.59 and 10.67/10,000), but these were double the incidence in white patients (5.07/10,000 eligible patients).

Discussion

Our findings do not support those of previous studies, which have suggested that BXO is predominantly a disease of middle-aged white men. In fact, in both black and Hispanic patients we noted an incidence twice that in whites. In addition, we found the highest incidence in young adults (in the third decade [13.71 cases/10,000]), with a relatively even distribution among all other age groups (Table 1).

To suggest an explanation for these findings, it is necessary to review the etiology of BXO. Although one single cause has not been definitively named, the many suspected causes carry the common denominator of chronic inflammation. Autoimmune phenomena have long been implicated in the progression to BXO, and a strong association with class II antigens has strengthened this argument significantly. In a study of 84 white female patients, Marren et al (9) showed a 78% concurrence with class II DQ human lymphocyte antigens in patients with lichen sclerosus et atrophicus. A history of trauma with resultant scarring and eventual progression to histologic BXO (ie, Kobner's phenomenon) has been noted in other studies. (10, 11) After hypospadias repair, BXO with urethral stricture has been reported in 0.4% (3 of 796 cases) (12) Various infectious agents, including human papilloma virus (serotype 16 in particular), spirochetes and atypical myco-bacteria, have been implicated in the progression to BXO, though this remai ns unsubstantiated.

The epidemiology of BXO is likewise uncertain. Most studies concur that the common distribution lies between the third and sixth decades. (13,14) Others address a correlation between BXO and late circumcision for phimosis and hypo-spadias repair. (12,15-17) These reports conclude that although BXO is regarded as a disease of the middle-aged, its prevalence in young boys is both underestimated and understudied. Approximately 35% of our patients treated for BXO had a history of late circumcision, genital trauma, or surgery for urethral stricture. The higher incidence among those aged 21 to 30 may be related to the high numbers of patients in that age group in the military receiving regular physical screenings, in comparison with veterans and dependent children. Our findings suggest that all other age groups are equally susceptible, except the very young (0-2 yr).

In addition, most previous studies have focused on the white population, only three reports discussing lichen sclerosus in patients of other ethnic backgrounds. (18-20) We found no published analysis of the demographics of BXO by ethnicity with which to compare our findings. One possible explanation for the ethnic differences in our study may be the better access to medical care for minorities through the military health care system. A second explanation might be cultural: at-birth circumcision was introduced into the United States by the white population, in whom the practice maintains greater popularity than in other ethnic groups. (21) Therefore, a higher percentage of phimosis and late circumcision among black and Hispanic men might not be surprising. A final explanation may be that BXO is more prevalent in regions with more temperate climates, as is penile cancer. Although BXO has not been putatively linked to squamous cell carcinoma, we believe that trends noted in our study could show BXO to be more pr ominent in tropical or subtropical regions. Further investigation of the comparative incidence in different regions and climates is warranted.

Conclusion

Our contemporary epidemiologic assessment of balanitis xerotica obliterans suggests that black and Hispanic patients have twice the risk of white patients of acquiring the disease. Second, BXO is a chronic inflammatory disease to which all age groups are equally susceptible, although it appears more frequently during the third decade. The range for diagnosis begins at approximately 2 years and continues well into the 80s and 90s. Finally, we recommend further research comparing the incidence of BXO in temperate and colder climates to assist in further identifying its cause.

Table 1

Incidence of balanitis xerotica obliterans by age group

                  No. of  Eligible
Decade of life  patients  patients        Incidence (a)

 0-10                 12    19,154   6.27 [+ or -] 3.54
11-20                  8    24,767   3.23 [+ or -] 2.24
21-30                 18    13,127  13.71 [+ or -] 6.33
31-40                 11    16,318   6.74 [+ or -] 3.98
41-50                 14    22,757   6.15 [+ or -] 3.22
51-60                 13    20,195   6.44 [+ or -] 3.50
61-70                 19    20,811   9.13 [+ or -] 4.10
71-80                 11    12,679   8.68 [+ or -] 5.12
81-90                  2     3,624   5.52 [+ or -] 7.65

(a) Per 10,000 eligible patients.

Table 2

Ethnic distribution of patients with balanitis xerotica obliterans

                 No. of   Eligible
Race/ethnicity  patients  patients     Incidence (a)

White              55      108,472   5.07 [+ or -] 1.34
Black              22       20,765  10.59 [+ or -] 4.42
Hispanic           24       22,503  10.67 [+ or -] 4.26
Other/unknown       7        1,692  41.37 [+ or -] 30.58

(a) Per 10,000 eligible patients

Accepted May 24, 2002.

References

(1.) Stuhmer A. Balanitis xcrotica obliterans (post-operationeur) und ihre bezichungen zur krauvosis glandis et preaputii penis. Arch Derm Syph (Berlin) 1928;156:613-623.

(2.) Habif TB. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. St. Louis, CV. Mosby, 1996, ed 3, p 228.

(3.) Bainbridge DR, Whitaker RH, Shepheard BG. Balanitis xerotica obliterans and urinary obstruction. Br J Urol 1971;43:487-491.

(4.) Ledwig PA, Weigand DA. Late circumcision and lichen sclerosus et atrophicus of the penis. J Am Acad Dermatol 1989;20:211-214.

(5.) Staff WG: Urethral involvement in balanitis xerotica obliterans. Br J Urol 1970;42:234-239.

(6.) Caterall RD, Oates JK. Treatment of balanitis xerotica obliterans with hydrocortisone injections. Br J Vener Dis 1962;38:75-77.

(7.) Laymon CW, Freeman C. Relationship of balanitis xerotica obliterans to lichen sclerosus et atrophicus. Arch Dermatol Syphilol 1955;49:57-59.

(8.) Garat JM, Chechile G, Algaba F, Santaularia JM. Balanitis xerotica obliterans in children. J Urol 1986;136:436-437.

(9.) Marren P, Yell J, Charnock FM, et al. The association between lichen sclerosus and antigens of the HLA system. Br J Dermatol 1995;132:197-203.

(10.) Pock L. Kobner phenomenon in lichen sclerosus et atrophicus. Dermatologica 1990;181:76-77.

(11.) Meffert JJ, Grimwood RE, Lichen selerosus et atrophicus appearing in an old bum scar. J Am Acad Dermatol 1994;31:671-673.

(12.) Uemura S, Hutson JM, Woodward AA, Kelly JH, Chow CW. Balanitis xerotica obliterans with urethral stricture after hypospadias repair. Pediatr Surg Int 2000;16:144-145.

(13.) Kumar MV, Harris DL. Balanitis xerotica obliterans complicating hypospadias repair. Br J Plast Surg 1999:52:69-71.

(14.) Jebakumar SP, Woolley PD. Balanitis xerotica obliterans. Int J STD AIDS 1995;6:81-83.

(15.) Rickwood AM, Hemalatha V, Bateup G, Spitz L. Phimosis in boys. Br J Urol 1980;52:147-150.

(16.) Meuli M, Briner J, Hanimann B, Sacher P. Lichen sclerosus et atrophicus causing phimosis in boys: A prospective study with 5-year followup after complete circumcision. J Urol 1994;152:987-989.

(17.) Meffert JJ, Davis BM, Grimwood RE. Lichen scierosus. J Am Acad Dermatol 1995;32:393-418.

(18.) Datta C, Dutta SK, Chaudhuri A. Histopathological and immunological studies in a cohort of balanitis xerotica obliterans. J Indian Med Assoc 1993;91:146-148.

(19.) Jacyk WK, Isaac F. Lichen sclerosus et atrophicus in Nigerians. J Natl Med Assoc 1979;71:387-388.

(20.) Wang JB, Yan H, Yang HY, et al. Histopathological and ultrastructural changes of lichen selerosus et atrophicus on the vulva. Chin Med J (Engl) 1991;104:868-871.

(21.) Hammond T: A preliminary poll of men circumcised in infancy or childhood. BJU Int 1999;83(Suppl 1):85-92.

RELATED ARTICLE: Key Points

* Black and Hispanic patients have twice the risk of white patients for acquiring balanitis xerotica obliterans.

* All age groups were susceptible to developing balanitis xerotica obliterans, with the diagnosis at approximately 2 years and continuing well into the 90s.

* The incidence of balanitis xerotica obliterans was higher among men in their third decade of life.

From the Department of Urology, Brooke Army Medical Center, Fort Sam Houston, TX.

Reprint requests to Allen F. Morcy, MD, Urology Service, 3851 Roger Brooke Drive, Fort Sam Houston, TX 78234-6200. Email: [e-mail]

The views expressed in this article are those of the authors and do not reflect the official policy or position of the U.S. Army, the U.S. Department of Defense, or the U.S. Government.

Copyright [c] 2003 by The Southern Medical Association 0038-4348/03/9601-0009