Alopecia areata, primary sclerosing cholangitis, and ulcerative colitis: autoimmunity and apoptosis as common links?

Impact of gut microbiome on skin health: gut-skin axis observed through the lenses of therapeutics and skin diseases

The human intestine hosts diverse microbial communities that play a significant role in maintaining gut-skin homeostasis. When the relationship between gut microbiome and the immune system is impaired, subsequent effects can be triggered on the skin, potentially promoting the development of skin diseases. The mechanisms through which the gut microbiome affects skin health are still unclear. Enhancing our understanding on the connection between skin and gut microbiome is needed to find novel ways to treat human skin disorders. In this review, we systematically evaluate current data regarding microbial ecology of healthy skin and gut, diet, pre- and probiotics, and antibiotics, on gut microbiome and their effects on skin health. We discuss potential mechanisms of the gut-skin axis and the link between the gut and skin-associated diseases, such as psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. This review will increase our understanding of the impacts of gut microbiome on skin conditions to aid in finding new medications for skin-associated diseases.

The Association between Alopecia and Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

IMPORTANCE

The link between autoimmune gut disorders and different types of hair loss conditions has been recently investigated with an increased interest. With acknowledgement of the connection between immune dysregulation and the gut microbiome, this pathway is now becoming recognized as playing an important role in hair growth. The inflammatory cascade that results from the disruption of gut integrity such as seen in inflammatory bowel diseases (IBD) has been associated with certain types of alopecia.

OBJECTIVE

The aim of this work was to evaluate the association between alopecia and IBD.

EVIDENCE REVIEW

A primary literature search was conducted using the PubMed, Embase, and Web of Science databases to identify articles on co-occurring alopecia and IBD from 1967 to 2020. A total of 79 studies were included in the review. A one-way proportional meta-analysis was performed on 19 of the studies to generate the pooled prevalence of alopecia and IBD.

FINDING

The pooled prevalence of non-scarring alopecia among IBD patients was 1.12% (k = 7, I2 = 98.6%, 95% CI 3.1-39.9); the prevalence of IBD among scarring and non-scarring alopecia was 1.99% (k = 12; I2 = 99%, 95% CI 6.2-34). The prevalence of non-scarring alopecia areata (AA) among IBD was compared to the prevalence of AA in the general population (0.63 vs. 0.1%; p < 0.0001). Similarly, the prevalence of IBD among the scarring and non-scarring alopecia groups was compared to the prevalence of IBD in the general population (1.99 vs. 0.396%; p = 0.0004).

CONCLUSION

IBD and alopecia, particularly AA, appear to be strongly associated. Dermatology patients with alopecia may benefit from screening for IBD.

Alopecia Universalis Associated with Ulcerative Colitis and The Role of Azathioprine

Skin manifestations can herald, co-exist, or follow the evolution of inflammatory bowel disease (IBD). We report a middle-aged man with recent onset alopecia universalis and a history of intermittent diarrheal attacks for 6 years. Colonscopy and biopsy sampling confirmed ulcerative colitis. Regrowth of hair was achieved by treating the patient with azathioprine and mesalamine. Clinicians have to be aware that a multitude of skin manifestations with history of diarrhea can be an extraintestinal manifestation of IBD such as ulcerative colitis and this warrants further investigation.

Symptom management in inflammatory bowel disease

Patients with inflammatory bowel disease can present with a wide variety of symptoms. Most are related to disease activity and should be managed with appropriate medical therapy for inflammatory bowel disease. However, some patients may develop symptoms due to the side effects of the medications, or due to immunosuppression. In these cases, the offending medications should be discontinued until resolution of the symptoms and a few may be able to restart therapy. Symptoms can also occur as an extraintestinal manifestation of the disease or due to concomitant autoimmune-mediated disorders. Regardless of the etiology, symptoms should be addressed promptly with immediate evaluation and appropriate therapy, as a delay may lead to permanent sequela.

Frequency and associated factors of hair loss among patients with inflammatory bowel disease

AIM: To identify the frequency of hair loss among patients with inflammatory bowel disease (IBD) and associated clinical and disease related factors.

METHODS: We performed a cross sectional study in a tertiary referral adult IBD clinic. Self-reported history and characteristics of hair loss as well as clinical and demographic information were collected. Data were analyzed using univariate and multivariate analyses.

RESULTS: Two hundred and ten consecutive IBD patients were recruited; one hundred and fifty patients met predefined inclusion and exclusion criteria. Thirty-three percent of patients reported a history of hair loss. Age, gender, IBD type and disease duration were not associated with hair loss. Hair loss was reported less frequently among patients with use of mesalamine (54% vs 73%, P = 0.03) and anti-tumor necrosis factor medications (anti-TNF) (14% vs 40%, P = 0.001). In multivariate analyses adjusting for gender, IBD type and duration of disease, these associations with mesalamine and anti-TNF remained significant [(adjusted values for mesalamine (OR = 0.43, 95%CI: 0.19-0.86) and anti-TNFs (OR = 0.28, 95%CI: 0.08-0.98)].

CONCLUSION: Hair loss is common among patients with IBD. Mesalamine and anti-TNF medications were associated with lower odds of hair loss. Further studies are required to assess the mechanism of hair loss among patients with IBD.