Association between geographic tongue and psoriasis: A systematic review and meta‐analyses

Abstract

Geographic tongue (GT) has been described as a predictor of psoriasis. The objective of this study was to analyse the prevalence of GT in psoriatic and non‐psoriatic patients. For this purpose, we conducted a systematic review and meta‐analysis. A literature search was performed on PubMed, Embase, Web of Science and the Cochrane Database of Systematic Reviews. The search and selection process was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) criteria. Only case‐control studies were selected, and the prevalence of GT in both groups was compared. Eleven articles met the inclusion criteria, and the frequency of GT was statistically associated with psoriasis in ten studies. The pooled odds ratio (OR) was 3.53 (95% confidence interval [CI] 2.56‐4.86). There were no significant differences between the presence of GT and the clinical form. However, the Psoriasis Area and Severity Index (PASI) score was statistically higher in patients affected by GT in three of four studies. Psoriatic patients with GT also exhibited less improvement in the PASI score after treatment. One study found an association between GT and a negative impact on patients’ quality of life. Nevertheless, age, gender, toxic habits, psoriasis onset and duration of the disease were not clearly associated. The results support the concept of GT as a manifestation of psoriasis. Future research should focus on the repercussions of GT in psoriatic patients, due to the negative consequences on severity and treatment response.

Psoriasis is associated with fissured tongue but not geographic tongue: a prospective, cross‐sectional, case‐control study

“…As there is evidence for a genetic background for both GT and psoriasis with well documented associations with susceptibility regions such as PSORS1, HLA antigens or with specific mutations such as in the IL36RN gene, one explanation might be differences in the genetic makeup of studied cohorts [28–31]. Corroborating this hypothesis, the percentage of healthy volunteers with GT in our study was also low (2.3 %) compared to other studies in which prevalence rates of GT in control groups ranged from 0.88 % to 9 % (mean = 5.2 %) [16]. Thus, it is conceivable that different prevalence rates of GT between ethnicities and geographic regions might lead to divergent results in studies on the association of GT with psoriasis [16, 19, 22].…”

“…It has been published that GT and FT are associated with psoriasis [7, 9, 14, 16, 24, 26]. Furthermore, it has been speculated that GT, due to its histological resemblance with psoriasis, might constitute a form of “oral psoriasis”, a notion which has recently been supported by a meta‐analysis [16, 27].…”

“…However, biopsy is usually not required as relevant differential diagnoses such as oral candidiasis, tongue conditions due to nutritional deficiencies such as iron or vitamin B12 deficiency, oral lichen planus, lichenoid mucosal reactions to amalgam or drugs and other forms of leukoplakia including oral hairy leukoplakia and premalignant conditions can be accurately distinguished on clinical grounds [17]. Geographic tongue has been associated with a variety of diseases such as atopic dermatitis, diabetes, reactive bronchitis, anemia, stress, hormonal disturbances, Reiter’s and Down’s syndromes, lithium therapy and psoriasis [7–9, 11, 13, 14, 16, 18–20]. Nevertheless, some reports have contradicted the association of psoriasis and GT [16, 18, 19].…”

“…Geographic tongue has been associated with a variety of diseases such as atopic dermatitis, diabetes, reactive bronchitis, anemia, stress, hormonal disturbances, Reiter’s and Down’s syndromes, lithium therapy and psoriasis [7–9, 11, 13, 14, 16, 18–20]. Nevertheless, some reports have contradicted the association of psoriasis and GT [16, 18, 19].…”

Increased levels of calprotectin in the saliva of patients with geographic tongue

“…In our study, 2/23 patients with GT reported that they suffered from psoriasis. In a recently published meta‐analysis, it was concluded from ten studies that there is a statistically significant association between the frequencies of GT and psoriasis (Gonzalez‐Alvarez, Garcia‐Martin, & Garcia‐Pola, ). However, it is not yet possible to draw the conclusion that some autoimmune factor is linked to the etiology of GT.…”