A thorough cutaneous examination includes the hair, nails, and mucous membranes (lips, intraoral mucosa, conjunctiva, genital). Admittedly, my exams are not that comprehensive. I’m not going to give myself a tongue lashing over it, but I usually do not look inside the mouth (or at other mucous membranes), unless the patient has symptoms at those sites or if I’m doing a directed exam; such as looking for reticulation of the buccal mucosa when suspecting lichen planus, or the conjuctivae when considering mucous membrane pemphigoid.
FT is a normal variant characterized by in increased number of fissures and grooves on the central and lateral aspects of the tongue. Up to 30% of the population displays FT. More severe fissuring is also known as “lingua plicata” – I always thought the term “scrotal tongue” was an apt morphologic descriptor, but have opted not to use it (I imagine most patients would prefer not having that diagnosis). FT is asymptomatic and is more common in older people. (2)
FT is idiopathic, although familial forms with dominant inheritance have been reported. (3) It is more common in people with geographic tongue (GT) and in patients with psoriasis, being observed in up to a third of cases. FT is also associated with Down syndrome, Melkersson-Rosenthal syndrome, pernicious anemia, pachyonychia congenita and Cowden syndrome. Although there is no consistently effective treatment for FT, good oral hygiene (including brushing the tongue into the fissures to diminish the microbial burden) is recommended to reduce halitosis. (2) D’Erme et al reported the case of a 60 year-old man with psoriasis and FT; after a 5-month course of infliximab, his FT demonstrated marked improvement. (4)
The literature on the oral manifestations of psoriasis is vast. One example, by Darwazeh et al, compared the oral examinations of 100 psoriatic patients to 100 closely matched controls. Oral mucosal lesions were diagnosed in 43 (43%) psoriatic patients and 17 (17%) control subjects. Comparing psoriatic patients to control subjects the prevalence of FT was 35% vs. 13%; GT 17% vs. 9%; combination of FT and GT 5% vs. 5%; oral candidosis 3% vs. 0%; leukoedema 1% vs. 3%; physiologic melanin pigmentations 4% vs. 1% respectively. The clinical type of psoriasis, duration of the disease, method of disease management, smoking habits, psychological status, or the disease severity did not influence the prevalence of FT or GT. Psoriatic patients who experienced a “very large” to “extremely large” adverse effect of psoriasis on their quality of life had a significantly higher prevalence of GT. The authors concluded that FT is significantly more common in psoriatic patients compared to controls. (5)
GT (benign migratory glossitis) affects 1-2% of the population, is more common in young patients, and often diminishes with age. (2) According to Picciani et al, “The association between geographic tongue and psoriasis has been demonstrated in various studies, based on observation of its fundamental lesions, microscopic similarity between the two conditions and the presence of a common genetic marker, human leukocyte antigen (HLA) HLA-C*06. The difficulty however in accepting the diagnosis of geographic tongue as oral psoriasis is the fact that not all patients with geographic tongue present psoriasis. Some authors believe that the prevalence of geographic tongue would be much greater if psoriatic patients underwent thorough oral examination.” (6)
The incidence of GT is reported to be higher in patients with early psoriasis (onset prior to 30 year old) and FT in late onset psoriasis (7). In the article that piqued my interest, the “branching and diffused” pattern of FT with moderate to severe scale was more frequently observed in psoriatic patients, as opposed to central longitudinal and branching in non-psoriatic patients with FT. (1)
This difference in FT patterns in psoriatic patients warrants explanation and further research. I wish I could present a good hypothesis but I am totally tongue-tied. Perhaps it is time for dermatologists to ask our patients to open their mouths and say “ahhh”.
Point to Remember: Fissured tongues are more common in psoriatic patients.
- Picciani BLS, et al. Fissured tongue in patients with psoriasis. J Am Acad Dermatol 2018; 78: 413-4.
- Mangold AR, et al. Diseases of the tongue. Clin Dermatol 2016; 34: 458-69.
- Tobias N. Scrotal tongue in its inheritance. Arch Derm Syphilol 1945; 52: 266.
- D’Erme AM, et al Fissured tongue responding to biologics during the treatment of psoriasis: the importance of detecting oral involvement of psoriasis. Dermatol Ther 2013; 26: 364-6.
- Darwazeh AMG, et al. Prevalence of oral mucosal lesions in psoriatic patients: A controlled study. J Clin Exp Dent 2012; 4: e286-91.
- Picciani BLS, et al. Geographic tongue and psoriasis: Clinical, histopathological, immunohistochemical and genetic correlation – a literature review. An Bras Dermatol 2016; 91: 410-21.
- Picciiani BLS, et al. Geographic tongue and fissured tongue in 348 patients with psoriasis: Correlation with disease severity. Scientific World Journal 2015; 2015:564326.
*Image is from Wikimedia Commons
Dermatology Insights and Inquiries (DI&I) is the 2017 Recipient of the AAD Sulzberger Dermatologic Institute and Education Grants Committee’s Program for Innovative Continuing Medical Education in Dermatology (PICMED) Grant. The PICMED project and DI&I are funded by an endowment established by the Skin Disease Education Foundation and the Elsevier Foundation.