Abstract
Objective: The aim of this study is to show another possible cause of oropharyngeal fibrosis causing breathing difficulty and dysphagia, and to demonstrate the possible effects of Khat chewing on the pharynx and larynx.
Study Design: Cross sectional study
Setting: Phoniatric Unit, Oto-Rhino-Laryngology department [removed for blind peer review]
Participants: This study included all patients using Khat referred to Phoniatric Unit due to different reasons during the period of March-2017 and September-2019.
Main outcome measures: A nine-question self-administered structured questionnaire was developed to covers all the socio-demographic factors in addition to Khat chewing habits. Full endoscopic evaluation was made and biopsies were obtained whenever possible. Patients were grouped into two groups; one using hot Khat (insecticide-irrigated) and the other using cold Khat (not insecticide-irrigated).
Results: The overall sample was 120 cases; 22 are using hot Khat and 98 cold Khat. Both groups are comparable with regard age, gender, smoking, duration of using Khat as well as its frequency. Reasons for referral for clinic were different between groups (p<0.001). Oropharyngeal stenotic lesions are (p< 0.0001) more frequent in the hot Khat group (77.3%) than in the cold Khat group (0%). In addition, chronic non-specific inflammation is significantly (p<0.0001) more frequent in the hot Khat group (68.2%) than in the cold Khat group (0%).
Conclusion: The relation between Khat chewing and oropharyngeal fibrosis can be proposed with strong relation to the use of pesticides. Further studies are recommended to confirm this relation.
Keywords: Khat chewing, oropharyngeal fibrosis, dysphagia, nasal obstruction, Yamen
Introduction:
Oropharyngeal fibrosis can be a result of traumatic element as in fracture of larynx and pharynx following car accidents. Trauma could result also from operation as in adenoidectomy, tonsillectomy or after radiotherapy for head and neck carcinoma. Chronic specific infection can cause fibrosis, including syphilis, tuberculosis (specially lupus tuberculosis), diphtheria, occasionally measles, leprosy and chronic pemphigus 1
Khat seems to affect the oral cavity and the digestive tract. A high frequency of periodontal disease has been suggested as well as gastritis and chronic recurrent subluxation and dislocation of the temperomandibular joint. Oral keratotic lesions at the site of chewing and plasma cell gingivitis (allergic reaction to Khat) have been reported. 2–5
Khat qat, q’at, gat, chat, tschat (Ethiopia), miraa (Kenya) is  recognized for its psychostimulant effects as  Ephedrine, Cocaine. The Khat, produces cathinone; an intermediate metabolite, and derivatives of cathinone are an emerging class of new psychoactive substances.6–8.
Across Europe, the most recent estimates suggest that Europe accounts for about 40% of the khat seized worldwide. The use of Khat has significantly increased in Europe in the past 20 years with the appearance of its different systemic side effects 9. Figure 1 showing Countries among EU Member States and Norway not specifically controlling khat under drugs laws, and estimates of khat seizures. 10.
There are no legal restrictions on cultivation, use, or age limits of use of Khat in Yemen, Ethiopia, Djibouti, Somalia and Kenya. For example, in Yemen, 15–20% of children under 12 years use Khat 11. The distributions of Khat consumption in the African horn and close by countries are shown in Figure 2 12.
Many health problems have been disseminated to different countries around the globe with the migration of khat users from East Africa and Arabia.13,14 Recent reports till 2011 suggested that currently 20 million people worldwide regularly used khat.14 This number has been escalated after Yemen crisis in 2015 according to mixed migration center(MMC)15
Widespread use of khat, especially its concurrent use with tobacco, remains a public health challenge in many countries including Asia, Europe, Australia, and the United States.13,14,16
Khat is consumed by chewing its fresh young leaves and twigs. The exudate is swallowed, and the residue spat out. In a typical single chewing session, 100– 500 gm of Khat over 3–4 h can be consumed.16–20 . The pattern of absorption of cathinone, cathine, and norephedrine in humans shows a two-compartment model with a two-segment absorption; the buccal mucosa is the first site of absorption and the small intestine the second site21. Fresh Khat has mood-enhancing properties similar to amphetamines. 17