Endometriosis




Abstract


Endometriosis is a common cause of pelvic, low back, and abdominal pain caused by the implantation of normal uterine endometrial mucosa in abnormal locations. Endometriosis occurs in approximately 8% of women with approximately 30% of these women completely asymptomatic. An estrogen-dependent disease, it usually affects reproductive aged women with an active hypothalamic-pituitary-ovarian axis. It is identified in approximately 35% of infertile women and in 80% of women suffering from chronic pelvic pain. There is a 10-fold increased incidence of endometriosis in those women who have a first-degree relative suffering from the disease with a locus on chromosome 7p15.2 lined to an increased incidence of endometriosis in women of European descent. There is also concordance in monozygotic twins. A suggestion is that there is an increased incidence of endometriosis and specific phenotypic traits including red hair, nevi, freckles, and sensitivity to sun exposure. Other risk factors for endometriosis include early menarche, prolonged heavy menstrual flow, and delayed first birth.


The pain of endometriosis is cyclical in that it accompanies menstruation. The onset of pain usually precedes menstrual flow by 48 hours and begins to resolve after 2 days of menstruation. The ameliorating effects of pregnancy and menopause are the rule, although hormone replacement therapy may cause a recurrence of the symptoms associated with endometriosis. The pain of endometriosis is not related to the load of abnormal implanted endometrial mucosa and stroma, but the location and depth of each endometrial implant




Keywords

endometriosis, pelvic pain, back pain, abdominal pain, ectopic pregnancy, ovarian cancer, endometrial cancer, dysmenorrhea, dyspareunia, dysuria, bowel obstruction

 


ICD-10 CODE N80.9




Keywords

endometriosis, pelvic pain, back pain, abdominal pain, ectopic pregnancy, ovarian cancer, endometrial cancer, dysmenorrhea, dyspareunia, dysuria, bowel obstruction

 


ICD-10 CODE N80.9




The Clinical Syndrome


Endometriosis is a common cause of pelvic, low back, and abdominal pain caused by the implantation of normal uterine endometrial mucosa in abnormal locations. Endometriosis occurs in approximately 8% of women with approximately 30% of these women completely asymptomatic. An estrogen-dependent disease, it usually affects reproductive aged women with an active hypothalamic-pituitary-ovarian axis. It is identified in approximately 35% of infertile women and in 80% of women suffering from chronic pelvic pain. There is a 10-fold increased incidence of endometriosis in those women who have a first-degree relative suffering from the disease with a locus on chromosome 7p15.2 lined to an increased incidence of endometriosis in women of European descent. There is also concordance in monozygotic twins. A suggestion is that there is an increased incidence of endometriosis and specific phenotypic traits including red hair, nevi, freckles, and sensitivity to sun exposure. Other risk factors for endometriosis include early menarche, prolonged heavy menstrual flow, and delayed first birth.


The symptomatology associated with endometriosis is summarized in Box 92.1 . The pain of endometriosis is cyclical in that it accompanies menstruation. The onset of pain usually precedes menstrual flow by 48 hours and begins to resolve after 2 days of menstruation. The ameliorating effects of pregnancy and menopause are the rule, although hormone replacement therapy may cause a recurrence of the symptoms associated with endometriosis. The pain of endometriosis is not related to the load of abnormal implanted endometrial mucosa and stroma, but the location and depth of each endometrial implant ( Fig. 92.1 ). There may also be bidirectional crosstalk between abnormal endometrial implants and subserving nerves as pain patterns become established ( Fig. 92.2 ). Psychometric testing suggests that patients suffering from symptomatic endometriosis have increased anxiety and neuroticism when compared with other female control groups. These symptoms may be exacerbated if the endometriosis is associated with infertility.



Box 92.1

Common Symptoms of Endometriosis





  • Dysmenorrhea



  • Pelvic pain



  • Lower abdominal pain



  • Lower back pain



  • Groin pain



  • Dyspareunia



  • Dysuria



  • Urinary frequency



  • Dyschezia





FIG 92.1


Classifications of nerve fibers and their relationship with eutopic and ectopic endometrium. , Efferent fibers; , afferent fibers; , increased density in women with endometriosis; , decreased density in women with endometriosis; , present in women with endometriosis only; , no differences between women with and without endometriosis. Ach, acetylcholine; CN, central nervous system; DA, dopamine; DRG, dorsal root ganglion; E, epinephrine; NE, norepinephrine; PNS, peripheral nervous system.

(Modified from Yan D, Liu X, Guo S-W. Nerve fibers and endometriotic lesions: partners in crime in inflicting pains in women with endometriosis. Eur J Obstet Gynecol Reprod Biol . 2017;209:14–24.)



FIG 92.2


Schematic illustration of possible cross-talks between endometriotic lesions and nerve fibers. Ach, Acetylcholine; ADRB2, β 2 adrenergic receptor; ASIC3, the acid sensing ion channel 3; BDNF, brain-derived neurotrophic factor; CGRP, calcitonin gene-related peptide; CX3CR1, CX3C chemokine receptor 1; GAP43, growth-associated protein 43; GDNF, glial-derived neurotrophic factor; KCNK, potassium channel subfamily K member; Na v 1.8, sodium voltage-gated ion channels; NE, norepinephrine; NGF, nerve growth factor; NK1R, neurokinin receptor 1; NMDAR, N-methyl- d -aspartic acid receptor; NT-3, neurotrophin-3; NT-4/5, neurotrophin-4/5; PGE 2 , prostaglandin E 2 ; P2XR3, P2X purinoceptor 3; SP, substance P; TRPV1, transient receptor potential cation channel subfamily V member 1; TXA 2 , thromboxane A 2 ; VEGF, vascular endothelial growth factor. The question mark (?) indicates the role of indicated molecule in endometriosis-associated pain, if any, is yet to be investigated.

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Sep 9, 2019 | Posted by in PAIN MEDICINE | Comments Off on Endometriosis

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