I'm wondering how many here have had microscopic colitis ruled out? Note that by "older adults", the title refers to over 50.
Microscopic Colitis — A Common Cause of Diarrhoea in Older Adults
Age and Ageing. 2010;39(2):162-168. © 2010 Oxford University Press
Abstract
Diarrhoeal diseases are common in older populations and often markedly affect their quality of life. Although there are numerous potential causes, microscopic colitis (MC) is increasingly recognised as a major diagnostic entity in older individuals. MC is comprised of two distinct histological forms — collagenous colitis and lymphocytic colitis, both of which frequently occur in older populations. Recent studies suggest that between 10 and 30% of older patients investigated for chronic diarrhoea with an endoscopically normal appearing colon will have MC. It is unclear why MC is more common in older populations, but it is associated with both autoimmune disorders and several drugs that are commonly used by seniors. A definitive diagnosis can only be made with colonic biopsies. Since MC was first described in 1976 and only recently recognised as a common cause of diarrhoea, many practising physicians may not be aware of this entity. In this review, we outline the epidemiology, risk factors associated with MC, its pathophysiology, the approach to diagnosis and the management of these individuals.
Introduction
At any one point in time, ~9% of an older out-patient population will be experiencing diarrhoea.[1] While the prevalence of chronic diarrhoea in older patients is unknown, it is a significant cause of morbidity among them — especially in vulnerable populations like those residing in long-term care facilities. In older populations, chronic diarrhoea can arise from a variety of conditions like coeliac disease and inflammatory bowel disease (IBD).[2] Microscopic colitis (MC) has emerged as a new and common cause of chronic diarrhoea in the general population.
MC is an umbrella term for a group of inflammatory diseases of the colon where the colonic lining appears endoscopically normal, but histologic examination on biopsy reveals increased intraepithelial lymphocytes (IEL) in the colonic mucosa. MC is subgrouped into two different forms that are characterised by histological means - lymphocytic and collagenous colitis. While both subgroups have increased numbers of IELs, a thickened collagen band on the basement membrane of the colonic epithelium is seen in the latter subtype.
MC is frequently associated with systemic disorders (such as hypothyroidism) and the use of certain medications. Not surprisingly, the disorder is being increasingly recognised as a common cause of diarrhoea in middle-aged and older patients. For many of these patients, especially women, the looser and/or more frequent movements may lead to rectal urgency and faecal incontinence or may result in a exacerbation of a previously controlled but latent insufficient anal sphincter.[3]
Epidemiology
When first described over 30 years ago, MC was believed to be rare.[4, 5] However, studies have shown that it is a common cause of watery diarrhoea, particularly in older female patients.[6] MC is a disease that predominantly affects older patients, with incidence rates anywhere from 5 to 10 times higher in those over 65.
Some population-based studies have looked at the incidence of MC in European and North American populations.[7–12] The overall total population annual incidence of collagenous colitis has ranged from 1.1 to 5.2 cases per 100,000 (Table 1) while the annual incidence of lymphocytic colitis per 100,000 was reportedly 3.1–5.5 (Table 1). More recent studies suggest an even higher incidence for MC. This is likely because of an increased awareness of the entity with more colonic biopsies being performed. For example, American incidence rates of 7.1 and 12.6 per 100,000 person-years for collagenous and lymphocytic colitis, respectively, were recently reported with a point prevalence for MC of 103.0 (39.3 for collagenous and 63.7 for lymphocytic colitis per 100,000).[11] Reports suggest that the incidence of MC approaches that of ulcerative colitis and Crohn's disease.[7]
Risk Factors and Disease Associations
Increasing age,[7–9] female sex,[7–9] autoimmune diseases such as thyroid disease[13] and coeliac disease,[14, 15] past or current diagnosis of malignancy[12, 16] and solid organ transplant are identified as risk factors for MC.[17]
The incidence of MC increases substantially with advancing age.[7–9] The mean age of diagnosis of the condition is in the fifth and sixth decades. In one Canadian study, patients greater than 65 years of age were more than five times as likely to have developed MC.[12] The reasons for this are unknown. While a genetic or environmental component seems possible since familial cases have also been reported,[18–20] MC does appear to be an age-associated condition.
Female sex is also a major risk factor.[7–9, 11, 21, 22] This predisposition is more pronounced for the collagenous colitis subtype. Population-based studies report a female to male ratio of 4.4–7.9:1 for collagenous and 1.8–5.0:1 for lymphocytic colitis.[7–12] The reasons for the higher rate among women are also unknown but might be related to the higher likelihood of autoimmune diseases, hormonal alterations and/or an ascertainment bias as women may be more likely to seek help for intermittent watery diarrhoea.
Autoimmune diseases, particularly thyroid and/or coeliac disease, are associated with MC.[8, 11, 13–15, 21–24] Fifty-three percent of patients with collagenous and 43% of patients with lymphocytic colitis have at least one concomitant autoimmune disease. Thyroid disease is found in 8.6 to 21% of those with MC.[7, 13, 14] A recent epidemiological study of 164 patients with MC found that 18 (11.0%) had a prior diagnosis of hypothyroidism.[12] Several studies have documented an association between coeliac disease and MC. Later studies have supported that coeliac disease is found in 6–15% with lymphocytic[22, 24] and 3–23% in patients with collagenous colitis.[14, 22] In a recent study conducted by our group, 7% of patients with a new diagnosis of MC had a prior diagnosis of coeliac disease, which was nearly eight times higher than the expected rate for the general population.[12]
The association of MC with neoplasia is less well studied. Several case reports have linked collagenous colitis with solid tumours[25, 26] and lymphoproliferative disorders.[27] Nearly 12% of patients with MC were found to have either a past or current diagnosis of malignancy.[12] After adjusting for age and sex, the risk was only higher in women over the age of 65. Other studies examining the risk of developing a malignancy after the diagnosis of MC have been unable to document an association.[16, 28]
Only one study has looked at solid organ transplant recipients.[17] The authors reported a point prevalence of 8.8 cases of MC per 1,000 solid organ transplant patients and an annual incidence rate of 5.0 per 1,000 transplant person-years. This incidence rate is ~50-fold higher than the rate found in the general population.
MC has been associated with the use of several medications including NSAIDs, SSRIs, beta-blockers, statins, biphosphonates, ticlopidine, flutamide and PPIs.[23, 29–31] A recent study showed that those with collagenous colitis more commonly consumed NSAIDs and SSRIs, than controls, while those with lymphocytic colitis more commonly consumed SSRIs, beta-blockers, statins and biphosphonates.[30] Other agents including PPIs,[31] ticlopidine[30] and flutamide[29] have been linked in case studies. There have been a few reports of symptom improvement with cessation of NSAIDs.[32]
Microscopic Colitis — A Common Cause of Diarrhoea in Older Adults
Age and Ageing. 2010;39(2):162-168. © 2010 Oxford University Press
Abstract
Diarrhoeal diseases are common in older populations and often markedly affect their quality of life. Although there are numerous potential causes, microscopic colitis (MC) is increasingly recognised as a major diagnostic entity in older individuals. MC is comprised of two distinct histological forms — collagenous colitis and lymphocytic colitis, both of which frequently occur in older populations. Recent studies suggest that between 10 and 30% of older patients investigated for chronic diarrhoea with an endoscopically normal appearing colon will have MC. It is unclear why MC is more common in older populations, but it is associated with both autoimmune disorders and several drugs that are commonly used by seniors. A definitive diagnosis can only be made with colonic biopsies. Since MC was first described in 1976 and only recently recognised as a common cause of diarrhoea, many practising physicians may not be aware of this entity. In this review, we outline the epidemiology, risk factors associated with MC, its pathophysiology, the approach to diagnosis and the management of these individuals.
Introduction
At any one point in time, ~9% of an older out-patient population will be experiencing diarrhoea.[1] While the prevalence of chronic diarrhoea in older patients is unknown, it is a significant cause of morbidity among them — especially in vulnerable populations like those residing in long-term care facilities. In older populations, chronic diarrhoea can arise from a variety of conditions like coeliac disease and inflammatory bowel disease (IBD).[2] Microscopic colitis (MC) has emerged as a new and common cause of chronic diarrhoea in the general population.
MC is an umbrella term for a group of inflammatory diseases of the colon where the colonic lining appears endoscopically normal, but histologic examination on biopsy reveals increased intraepithelial lymphocytes (IEL) in the colonic mucosa. MC is subgrouped into two different forms that are characterised by histological means - lymphocytic and collagenous colitis. While both subgroups have increased numbers of IELs, a thickened collagen band on the basement membrane of the colonic epithelium is seen in the latter subtype.
MC is frequently associated with systemic disorders (such as hypothyroidism) and the use of certain medications. Not surprisingly, the disorder is being increasingly recognised as a common cause of diarrhoea in middle-aged and older patients. For many of these patients, especially women, the looser and/or more frequent movements may lead to rectal urgency and faecal incontinence or may result in a exacerbation of a previously controlled but latent insufficient anal sphincter.[3]
Epidemiology
When first described over 30 years ago, MC was believed to be rare.[4, 5] However, studies have shown that it is a common cause of watery diarrhoea, particularly in older female patients.[6] MC is a disease that predominantly affects older patients, with incidence rates anywhere from 5 to 10 times higher in those over 65.
Some population-based studies have looked at the incidence of MC in European and North American populations.[7–12] The overall total population annual incidence of collagenous colitis has ranged from 1.1 to 5.2 cases per 100,000 (Table 1) while the annual incidence of lymphocytic colitis per 100,000 was reportedly 3.1–5.5 (Table 1). More recent studies suggest an even higher incidence for MC. This is likely because of an increased awareness of the entity with more colonic biopsies being performed. For example, American incidence rates of 7.1 and 12.6 per 100,000 person-years for collagenous and lymphocytic colitis, respectively, were recently reported with a point prevalence for MC of 103.0 (39.3 for collagenous and 63.7 for lymphocytic colitis per 100,000).[11] Reports suggest that the incidence of MC approaches that of ulcerative colitis and Crohn's disease.[7]
Risk Factors and Disease Associations
Increasing age,[7–9] female sex,[7–9] autoimmune diseases such as thyroid disease[13] and coeliac disease,[14, 15] past or current diagnosis of malignancy[12, 16] and solid organ transplant are identified as risk factors for MC.[17]
The incidence of MC increases substantially with advancing age.[7–9] The mean age of diagnosis of the condition is in the fifth and sixth decades. In one Canadian study, patients greater than 65 years of age were more than five times as likely to have developed MC.[12] The reasons for this are unknown. While a genetic or environmental component seems possible since familial cases have also been reported,[18–20] MC does appear to be an age-associated condition.
Female sex is also a major risk factor.[7–9, 11, 21, 22] This predisposition is more pronounced for the collagenous colitis subtype. Population-based studies report a female to male ratio of 4.4–7.9:1 for collagenous and 1.8–5.0:1 for lymphocytic colitis.[7–12] The reasons for the higher rate among women are also unknown but might be related to the higher likelihood of autoimmune diseases, hormonal alterations and/or an ascertainment bias as women may be more likely to seek help for intermittent watery diarrhoea.
Autoimmune diseases, particularly thyroid and/or coeliac disease, are associated with MC.[8, 11, 13–15, 21–24] Fifty-three percent of patients with collagenous and 43% of patients with lymphocytic colitis have at least one concomitant autoimmune disease. Thyroid disease is found in 8.6 to 21% of those with MC.[7, 13, 14] A recent epidemiological study of 164 patients with MC found that 18 (11.0%) had a prior diagnosis of hypothyroidism.[12] Several studies have documented an association between coeliac disease and MC. Later studies have supported that coeliac disease is found in 6–15% with lymphocytic[22, 24] and 3–23% in patients with collagenous colitis.[14, 22] In a recent study conducted by our group, 7% of patients with a new diagnosis of MC had a prior diagnosis of coeliac disease, which was nearly eight times higher than the expected rate for the general population.[12]
The association of MC with neoplasia is less well studied. Several case reports have linked collagenous colitis with solid tumours[25, 26] and lymphoproliferative disorders.[27] Nearly 12% of patients with MC were found to have either a past or current diagnosis of malignancy.[12] After adjusting for age and sex, the risk was only higher in women over the age of 65. Other studies examining the risk of developing a malignancy after the diagnosis of MC have been unable to document an association.[16, 28]
Only one study has looked at solid organ transplant recipients.[17] The authors reported a point prevalence of 8.8 cases of MC per 1,000 solid organ transplant patients and an annual incidence rate of 5.0 per 1,000 transplant person-years. This incidence rate is ~50-fold higher than the rate found in the general population.
MC has been associated with the use of several medications including NSAIDs, SSRIs, beta-blockers, statins, biphosphonates, ticlopidine, flutamide and PPIs.[23, 29–31] A recent study showed that those with collagenous colitis more commonly consumed NSAIDs and SSRIs, than controls, while those with lymphocytic colitis more commonly consumed SSRIs, beta-blockers, statins and biphosphonates.[30] Other agents including PPIs,[31] ticlopidine[30] and flutamide[29] have been linked in case studies. There have been a few reports of symptom improvement with cessation of NSAIDs.[32]
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