Bilateral meralgia paresthetica associatedwith pelvic inflammatory diseaseArthur S. Rotenberg, MD, CCFP

M eralgia paresthetica is a mononeuropathyinvolving the lateral femoral cutaneousnerve (LFCN), a purely sensory nerve that

innervates the lateral part of the thigh. The firstdescription of this disorder, in 1895, has beencredited to Bernhardt,' but Hager2 reported a case in1885. Sigmund Freud suffered from the conditionand reported the first bilateral case.3

The most common features of meralgia pares-thetica are numbness (in 48% of cases), decreasedsensation to pinprick (in 45%), pain (in 33%) andburning (in 21%).2,3 The most specific features areaggravation of the symptoms when the hip is extend-ed (e.g., during bedrest), a well-defined area ofsensory loss and a lack of motor abnormalities.4 6

Meralgia paresthetica is attributed largely toconditions such as obesity and pregnancy that exertpressure on the LFCN near the inguinal ligament.7'8Internal infections were once thought to be animportant cause8 but now are rarely associated withthe condition; this change may have been due to theintroduction of antibiotics. I describe a case in whichmeralgia paresthetica developed in a woman withpelvic inflammatory disease.

Case report

A 22-year-old woman presented with a 2-weekhistory of increasing abdominal pain and menorrha-gia associated with fever, chills, vomiting and diar-rhea. She had noted increasing dysmenorrhea afterreplacement of her intrauterine device severalmonths previously. On examination she had abdom-inal distension, guarding and rebound tenderness, aswell as marked tenderness of the cervix, uterus andadnexa. The erythrocyte sedimentation rate was 40mm/h, the leukocyte count was 18.8 x 1 09/L, and theresults of testing for the fl-subunit of human chorion-ic gonadotropin were negative. Diffuse peritonitisand bilateral salpingitis were found at laparoscopy,and culture of the peritoneal fluid yielded Chla-mydia.

Intravenous therapy was given for 1 week withdoxycycline, 100 mg twice daily, cefoxitin sodium, 1g every 6 hours, and metronidazole, 500 mg every 8hours. The associated ileus was severe enough torequire nasogastric suction and intravenous hydra-

tion for 5 days. After discharge from hospital thepatient received 2 weeks of oral therapy with ceph-alexin monohydrate, 500 mg every 6 hours, anddoxycycline, 100 mg twice daily.

During the hospital stay the patient noted painin the sacroiliac joints as well as a burning pain andnumbness in the lateral aspects of both thighs. Thesymptoms were worse when she was lying flat; therewere no other aggravating or relieving factors. Shefirst reported the pain and dysesthesia 1 month later.At that time she had decreased sensation to pinprickand light touch in bilateral elliptical areas of about20 x 10 cm in the regions supplied by the LFCNs.There was tenderness over the sacroiliac joints;however, there was no central back pain and nomotor or reflex abnormality. Straight leg raising andfemoral stretch testing did not aggravate the pain ordysesthesia. She had never been obese, worn tightbelts or been pregnant.

Over the next 6 months the back pain resolved,but a 6-cm area of burning, numbness and hypes-thesia remained in the regions supplied by theLFCN. There were no other abnormal neurologicfindings, and the patient was otherwise well. Theresults of a 3-hour glucose tolerance and VDRL testswere normal, as were the results of nerve conductionstudies in the legs and electromyography of thequadriceps on the right side.

Comments

It is widely accepted that meralgia parestheticais due to entrapment of the LFCN at the inguinalligament.4,69"0 An autopsy study revealed local de-myelination at that site, even in some subjects whohad no symptoms of peripheral neuropathy.9 Thissuggests that the nerve is vulnerable to subclinicaldamage. Perhaps pelvic inflammatory disease orother intra-abdominal inflammation can result infurther compression of the nerve and overt meralgiaparesthetica. This effect may occur at the inguinalligament or higher up, along the "long, exposedcourse"" of the LFCN. Suber and Massey'2 reporteda case in which compression of the lumbar plexus bya uterine leiomyoma had been discovered at surgery;the meralgia resolved after myomectomy.

Some early descriptions of meralgia paresthetica

From the Department ofFamily Medicine, North York General Hospital, Willowdale, Ont.

Reprint requests to: Dr. Arthur S. Rotenberg, 45 Glendora Ave., Willowdale, Ont. M2N 2V8

42 CAN MED ASSOC J 1990; 142 (1)

emphasized infection as the cause.'7 Infection hasbecome a less important cause, perhaps because ofthe introduction of antibiotics and the associatedreduction in the severity of internal infections. Thepatient I have described had sufficient pelvic infec-tion to cause ileus; this indicates a severity morecharacteristic of the preantibiotic era.

A search of the Medline database and thebibliographies of all available review articles onmeralgia paresthetica did not yield any reports of anassociation between this neuropathy and pelvic in-flammatory disease. In one article the authors statedthat pelvic inflammatory disease, enterocolitis andappendicitis were all possible causes, but they gaveno supporting documentation.8 In several reportsmeralgia paresthetica was associated with processessuch as appendicitis, colitis and postoperative in-flammation.'78'3 In one case transient meralgiaparesthetica was observed after abdominal hysterec-tomy and was thought to have been caused bypostoperative inflammation.'3

The mechanical effects of infection or inflam-mation on the LFCN may well have been themechanism in the case reported here; they may alsoexplain earlier reports of meralgia paresthetica afterinternal infection or abdominal surgery.

I thank Drs. Michael Rasminsky and Greg DeMarchi fortheir assistance in preparing the article.

References

1. Bernhardt M: Uber isolirt im Gebiete des Nervus cutaneusfemoris externus vorgommende Parasthesien. Neurol Cen-tralbl 1895; 14: 242-244

2. Hager W: Neuralgia femoris: Resection des Nervus cutaneusfemoris anterior externus. Heilung. Dtsch Med Wochenschr1885; 11: 218

3. Freud S: Ueber die Bernhardt'sche Sensibilitatsstorung amOberschenkel. Neurol Centralbl 1895; 14: 491-492

4. Streiffer RH: Meralgia paresthetica. Am Fam Physician 1986;33: 141-144

5. Teng P: Meralgia paresthetica. Bull Los Angeles Neurol Soc1972; 37: 75-83

6. Stookey B: Meralgia paresthetica: etiology and surgical treat-ment. JAMA 1928; 90: 1705-1707

7. Kitchen C, Simpson J: Meralgia paresthetica: a review of 67patients. Acta Neurol Scand 1972; 48: 547-555

8. Chhuttani PN, Chawla LS, Sharma TD: Meralgia pares-thetica. Acta Neurol Scand 1966; 42: 483-490

9. Jefferson D, Eames RA: Subclinical entrapment of the lateralfemoral cutaneous nerve: an autopsy study. Muscle Nerve1979; 2:145-154

10. Dyck PJ, Low PA, Stevens JC: Diseases of peripheral nerves.In Baker AB, Joynt RB (eds): Clinical Neurology, vol 4,Har-Row, Philadelphia, 1986: 47

11. Stevens H: Meralgia paresthetica. AMA Arch Neurol Psychia-try 1957; 77: 557-574

12. Suber DA, Massey EW: Pelvic mass presenting as meralgiaparesthetica. Obstet Gynecol 1979; 53: 257-258

13. Eskens HR: Meralgia paresthetica in women [C]. Am EarnPhysician 1986; 34: 2

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