IMPORTANCEHidradenitis suppurativa (HS) is associated with a number of physical and psychological comorbidities.Studies have suggested an association between HS and anemia; however, this association is not widely understood and may result in delayed diagnosis and treatment and possible increase in morbidity and mortality.
OBJECTIVETo systematically review and perform a metanalysis regarding the association between HS and anemia, and to characterize the subtypes of anemia associated with HS.
DATA SOURCESA search of the EMBASE, Medline, Web of Science Core Collection, and Cochrane Central Register of Controlled Trials databases from the time of database inception to September 25, 2022, yielded 313 unique articles.
STUDY SELECTIONAll observational studies and randomized controlled trials published in English that examined the odds ratio (OR) of anemia in patients with HS were screened by 2 independent reviewers. Case reports were excluded. Among 313 unique articles, 7 were deemed eligible.
DATA EXTRACTION AND SYNTHESISThe Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines facilitated data extraction. The Newcastle-Ottawa Scale (NOS) was used to analyze risk of bias of included studies. In addition to OR and 95% con dence intervals, relevant data on patient demographics and anemia subtypes were also extracted.
MAIN OUTCOMES AND MEASURESThe primary outcome was the OR of anemia in HS patients. This study also attempted to characterize anemia subtypes associated with HS.
RESULTSIn total, 2 case-control and 5 cross-sectional studies featured a total of 11,693 patients. Among the studies, 4 of 7 demonstrated a statistically signi cant positive association between anemia and HS (ORs, 2.20 [1.42 to 3.41], 2.33 [1.99 to 2.73], 1.87 [1.02 to 3.44], and 1.50 [1.43 to 1.57]), with macrocytic and microcytic subtypes being most common. After adjusting for publication bias, meta-analysis with Page 3/15 random effects revealed HS to be associated with increased odds of anemia compared to non-HS groups (OR 1.59 [1.19, 2.11
])
CONCLUSIONS AND RELEVANCEThere is a statistically signi cant positive association between HS and anemia, particularly for the aforementioned subtypes. Patients with HS should be screened for anemia. In case of lower hemoglobin concentration, the anemia of HS patients should be subdivided according to mean corpuscular volume of the red blood cells and further investigated depending on subtype.
Key PointsQuestion What are the odds of anemia in patients with hidradenitis suppurativa (HS)? Findings This meta-analysis featured 7 total studies (2 case-control and 5 cross-sectional) comprising 11,693 participants. Meta-analysis revealed HS to be associated with increased odds of anemia compared to non-HS groups. Three studies found an association with microcytic anemia and two with macrocytic anemia.Meaning Patients with HS should be screened for anemia. In case of lower hemoglobin concentration, the anemia of HS patients should be subdivided according to mean corpuscular volume of ...
