Diagnosis and management of psychogenic oral paraesthesia

1 - DIAGNOSIS

Psychogenic oral paresthesia is an unpleasant sensation of tingling or pricking, or a feeling of swelling or burning, with spontaneous onset. It is similar to pruritus of the skin although it is not accompanied by a need to scratch the oral mucosa. Without appropriate management, the patient may experience it as unbearably painful and it can become chronic, leading to an obsessional and disabling psychogenic preoccupation.

Numerous different names have been used because it has been difficult to connect these symptoms to an organic cause that can be objectively identified in clinical examination or other medical examinations. The oldest terms (rhumatismus linguae, glossalgia, lingual neuralgia, imaginary ulcerations of the tongue) are obsolete, as is the term glossodynia (from the Greek odunè meaning pain) coined in 1885 by Kaposi, although it is sometimes still used to describe the intense tongue pain that is characterised mainly by a burning sensation (glossopyrosis). The terms stomatodynia (SD) and burning mouth syndrome (BMS) are currently the most commonly used and this can be considered to be a step forward as these terms indicate that the “pains” may be situated in other parts of the mouth, and they introduce the notion of a syndrome, which sometimes includes salivary and gustatory problems. The condition is defined as a collection of sensations that cause varying degrees of pain and discomfort which cannot be explained by any detectable local abnormality. This has culminated in a number of etiologic theories, and has drawn attention to the problems of anxiety and depression that the majority of these patients present, which are considered by some authors to be a consequence of the syndrome, and by others as a possible cause.

In many of the articles about SD or BMS, the rather perfunctory clinical description of patients, gives the impression that the symptoms are always more or less the same and that the differences lie mainly in the various causes of a unique condition:

– SD of local cause, such as a candidiasis, an allergy, a dental prosthesis causing irritation, or dry mouth, none of which fits in with the idea of there being no detectable local abnormality;

– SD of systemic cause, such as problems related to menopause, anaemia, nutritional deficiency, diabetes;

– essential or idiopathic SD, which is the most common type but is diagnosed by exclusion, and which could correlate to a possible role for problems of anxiety or depression or a hypothetical local neuropathy.

A more recent idea is to reserve the name SD or BMS for the primary essential SD and the systemic SD. This would Imply that the local secondary paresthesia , and the cases that usually do not include the other symptoms of this syndrome should be excluded and considered as “differential diagnosis”.

Les PBP sont observées principalement chez les femmes (environ 4 à 5 fois plus que les hommes), à partir de l’âge de 40 ans, avec un pic entre 50 et 70 ans. Les cas avant 40 ans sont rares, avant 30 ans presque inexistants. La prévalence variable (de 0.7 à 2.6%) s’élèverait jusqu’à 10 à 40% chez les femmes consultant pour les troubles de ménopause. Selon notre expérience, les PBP concernent plus d’un tiers de l’activité d’une consultation spécialisée des affections de la muqueuse buccale.

Les patients ont souvent consulté de nombreux praticiens, depuis des années. Les patients évoquent souvent de multiples médicaments « qui n’ont rien fait » ou ont aggravé leur mal ; ilsproduisent des liasses d’examens complémentaires. Souvent un traitement dentaire, la mise en place de prothèse, un dentifrice, ou un aliment habituel est présenté comme étant à l’origine du mal. Le patient apporte souvent un diagnostic organique auquel il adhère, par exemple, une « allergie » de cause inconnue qui ne guérit pas, une « candidose » qui persiste depuis des mois et résiste à tout traitement. Il est important de reprendre l’interrogatoire de manière systématique mais en évitant toute suggestion et en s’adressant directement au patient, et non à la personne qui, souvent, l’accompagne.

Psychogenic oral paresthesia (POP) is mainly seen in women (around four to five times more often than in men), from the age of 40, peaking between 50 and 70 years. Cases seen before the age of 40 are rare, and before 30, almost non-existent. The variable prevalence (between 0.7 and 2.6%) is thought to rise to around 10 to 40% in women attending for problems related to the menopause. In our experience, POP accounts for more than one third of the workload of specialists of diseases of the oral mucosa.

Patients have often consulted a number of practitioners over several years. Patients often describe having used numerous medications that have “done nothing” or aggravated their symptoms; they produce piles of additional examination reports. Often it is a dental treatment, the fitting of a dental prosthesis, or the consumption of an unusual food that is presented to be the cause of the problem. The patient is often firmly convinced of an organic diagnosis such as an “allergy” of unknown cause that will not resolve, or “candidiasis” that lasts for several months and is resistant to all treatments. It is important to systematically take a full history while avoiding all suggestions and addressing directly the patient rather than the attending companion.

Des troubles salivaires sont évoqués dans plus de 2 tiers des cas, le plus souvent une sensation de sécheresse de la bouche, ou seulement des lèvres. Paradoxalement, elle ne cause pas de dysphagie, il n’est pas nécessaire de prendre une gorgée d’eau pour avaler un aliment sec comme une bouchée de pain ou une biscote. Certains patients se plaignent au contraire d’un excès de salive les obligeant à avaler ou cracher sans arrêt, cet état peut coexister avec des phases de sécheresse.

The paresthesia, the features of which the patient will be asked to describe – from a feeling of “swelling” to a burning sensation – do not occur “in the whole of the mouth”. It has a specific site that the patient must be asked to pinpoint. The experienced clinician will be sensitive to the patient’s verbal and non-verbal manifestations of feelings, the latter also having diagnostic value. usually the tongue that is affected, either at the tip or the anterior third, and it is rarely just one side; Usually the patient vaguely gestures to his barely drawn out tongue, but some patients will pull their tongue out to quite an impressive extent, especially when paresthesia occurs in the foliate papillae area. Other common sites are the labial mucosa or red border, especially of the lower lip; the mid anterior gingivo-palatine region, with rare cases affecting the vestibular gingival or the posterior palate; and sometimes the oropharynx with a prickling sensation or a feeling of having “a lump in the throat”. The paresthesia is intermittent at first, later becoming a daily occurrence, appearing late in the day then increasingly earlier in the morning after breakfast, and in rare cases a few minutes after waking up. They become gradually more intense over the course of the day, being felt most strongly in the evening before falling asleep. They fluctuate, becoming worse in stressful situations or moments of conflict, and – the key feature – they swiftly ease off and disappear during a meal, or even with a sweet or a glass of water, gradually returning afterwards. They can make it difficult for the patient to fall asleep but they do not wake them up during the night.

Problems with salivation are described in two thirds of cases, usually feeling of dryness in the mouth, or sometimes only in the lips. Paradoxically, this does not lead to dysphagia, and patients do not need to take a mouthful of water to help them to swallow dry foods like crusty bread or toast. Some patients, by contrast, complain of excessive saliva, that means they have to constantly swallow or spit, although this can coexist with phases of dryness.

Gustatory problems are the source of complaints in one quarter of cases: phantogeusia, in which a salty, metallic, bitter or rotten taste is present in the absence of any gustatory stimulus; the feeling of an acidic discharge from an upper premolar or molar; and dysgeusia, in which a sweet food can be perceived as savoury or bitter; or complete loss of the sensation of taste, which is known to be in large part related with troubles of olfactory sensitivity, but patients only rarely report this directly.

Other problems that we know may have a partly psychosomatic origin are sometimes associated: irritable bowel syndrome, tinnitus, and various kinds of headaches described as “migraines”.

Problems of anxiety and/or depression are set out carefully and gradually. It is common for a phobia of cancer or of infections, particularly AIDS, to be gradually revealed. The clinical examination of the mucosa does not identify anything that is likely to be the cause of the paresthesia. The clinician should explain to the patient that the bizarre aspects that cause him concern, such as foliate papillae or Fordyce spots, are in fact normal structures. Some abnormalities are due to somatic presentations of the anxiety that can accompany POP, such as sucking and aspirating tics that trigger an abnormally protruding linea alba of the cheeks or nodules of fibrous hyperplasia of the lower lip, labio lingual hyperkinesia with erythematous areas of friction, and bruxism, a major cause of dental abrasion and sometimes of hypertrophy of the masseter muscle.

Other objective abnormalities possibly related to POP are considered during differential diagnosis. The saliva sometimes has a foamy appearance, and except in already treated patients, usually the mucosa is not dry, and it does not stick to the dental mirror. Non-stimulated saliva flow –can be simply estimated by observing one by one the excretory orifices while massaging the corresponding gland, or in a patient keeping for a while a bowed head and an open mouth, by waiting for the formation of a “pool of saliva” on the anterior floor of the mouth. It seems to be normal, in contrast to the subjective feeling of dryness. When measured precisely it is often found to be moderately reduced, and possible causes for this could be medications, especially psychotropic drugs, or it could be a functional consequence of depression. In this way the clinical examination and a few additional examinations that together confirm the absence of any local disorder contribute to the task of reassuring the patient, although this may turn out to be arduous. 

There is no further test or examination that can confirm or refute a diagnosis of POP. A biopsy of the mucosa or minor salivary glands of the lower lip must be avoided because there is a risk of the patient developing an anxious fixation around the wound and pain involved in the procedure, leading to aggravation of symptoms. A few non-invasive examinations, a short list to be chosen depending on the clinical presentation, can assist with differential diagnosis, It should include at least a full blood count, and possibly a swab for mycology, a series of epicutaneous allergy tests, a glycaemia, and serum iron or vitamin B12 test.

Differential diagnosis and diagnosis of etiology in POP takes into account all aspects of the syndrome, mainly paresthesia, but also salivary and gustatory problems. First of all, paresthesia that has previously been termed as having a “local cause” should be excluded, and the etiological role of conditions considered to be a possible systemic cause, or which be responsible for essential SD, should be discussed. An absence of the other symptoms of POP is not always a sufficient argument, as non-psychogenic secondary paresthesia can complicate anxiety or depression, leading to a simulacrum of the POP syndrome that is always missing certain characteristic signs, such as remission during meals. The following may also be considered:

– A contact allergic reaction or irritant dermatitis: this topic is the subject for a separate discussion.

– Candidiasis, especially a chronic, erythematous form, usually with no functional impact. This diagnosis should never be based only on mycological examination results: an inflammatory reaction must be seen that must regress with anti-fungal treatment within a few days at most.

– Xerostomia, a primary symptom of Sjögren’s syndrome that may also be secondary to conditions such as lupus erythematosus or the use of numerous medications, may be accompanied more often by swallowing problems than paresthesia. The difficulties caused by this objective dryness increase during meals.

– Certain conditions of the oral mucosa: very often geographic tongue and lichen planus are deemed to be the cause when they are found in patients reporting POP. These conditions have usually been present long before the onset of POP, which has a different site from that of the mucosal lesions.

– Gustatory dysfunction, which may be isolated or sometimes accompanied by a lack of saliva, can be due to use of some medications such as antibiotics, anti-fungal drugs, antidepressants etc.

– Dental prosthesis or implants, whether old or poorly fitted, or new and poorly tolerated or not accepted: bad dental positioning can lead to discomfort, pain and trauma, but not paraesthesia.

– Oral galvanic effect: If different metals are present in the saliva this can act like a battery and produce an electric current, but is too weak to lead to paraesthesia. Replacing the dental implants suspected to be causing it is an expensive process that almost always fails and often aggravates symptoms.

– Gastroesophageal reflux with acid regurgitations in the mouth can damage tooth enamel, cause gustatory changes, and lead to intermittent burning sensations of the mouth and pharynx that differ from POP.

– A hormone imbalance, especially during the menopause, can be accompanied by the onset of isolated or POP-type paresthesia. The true cause could be depressive mood, since the syndrome can precede the menopause and persist over years in spite of hormone treatment, and it can affect men.

– Localised peripheral neuropathy, a candidate for treatment attempts with capsaicin or alpha-lipoic acid, although their efficacy has been disputed.

– A deficiency of zinc, iron, folic acid or vitamins B1, B2, B6, B12 can cause paresthesia. This is seen in iron deficiency anaemia and Plummer-Vinson syndrome, which is accompanied by mucosal atrophy and is reversible when treated with iron supplements. Pernicious anaemia can be identified due to the appearance of erythematous macules on the tongue or lips and oral paresthesia that differs from POP because it is exacerbated by eating.

2 - MANAGEMENT OF POP

2.1 - A PSYCHOGENIC ETHIOLOGY

We have proposed the term psychogenic oral paresthesia (POP) to characterize a syndrome that combines oral paresthesia, salivary problems, gustatory problems, and anxiety or depression. These latter symptoms may be more or less marked, but they are always present and add a specific character to the syndrome, which ceases to be a diagnosis of exclusion and can be considered from the very beginning.

The fact that antidepressant, anxiolytic, psychotherapeutic and behavioural treatments often lead to a significant improvement or indeed a complete resolution of this type of paresthesia leads us to believe, until there is proof to the contrary, that anxiety or depression are the cause of these sensations rather than a consequence of them, and that it represents therefore a psychosomatic symptom. If these sensations, often experienced by patients as painful, have a psychogenic etiology, then we can understand that a treatment directed against pain will not work, and bears the risk of constantly increasing doses.

A psychosomatic symptom

We have analytically listened to patients with POP and this has enabled us to pinpoint the psychological mechanisms that lead to psychogenic oral paresthesia, in keeping with the notion of archaic depression, i.e. relating to lived experience in the first few months of life. This early depression corresponds to the difficulty of tolerating the first separation between mother and infant, difficulty transforming the “skin to skin” contact into a psychological relationship with another person. The affected patients rarely present the classic symptoms of depression, but mainly somatic, functional or behavioural symptoms. Walcher introduced the term “ larvierte Depression” i.e "hidden", or "masked depression" in 1969, also called “essential depression” by the French psychosomatic school.

POP can be the reappearance of a traumatic separation experience

Having listened to our patients who have developed oral paresthesia, we have formed the hypothesis that life events in the personal history of each patient, anchored to their physical well-being (oral-dental care, surgery etc.) or their relationships (changes in relationships, loss, new life circumstances etc.), cause the patient to “relive” an early loss, the loss of a feeling of continuity between the mouth and the bottle/breast, this sensation normally being replaced, at the time of weaning, by a mental representation. For these patients, certain events in adult life lead to a partial (reversible) deconstruction of these mental representations of the mouth, a deterioration of what psychoanalysts call “unconscious body image”] that is restricted to the mouth.

The reports of our patients lead us to believe that the paresthesia may be the reappearance of a traumatic separation experience, which is why the mouth is the site of sensations of burning, pricking, swelling etc. There is indeed a wound but it is not organic; it concerns the patient’s “psychic envelope”, according to the theory of the “skin ego".

Irritating and painful sensations and lingual hyperkinesia can be used by the unconscious to “soothe” this psychological “wound” and to defend oneself against depressive anxiety, a normal and transient anxiety that accompanies the journey through the depressive stage, a step in the psychological development of all young children, observed for example in the form of the anxiety of an 8-month old baby faced with a stranger. If this stage is not overcome, this leads to a “psychosomatic potential”, which means using the body to express feelings of discomfort. 

The affective and emotional dimension of our system of perception, as well as “neuronal plasticity” [19, 20], which are consistent with the concept of a unique and individual unconscious body image, mean we can accept that the irritating or painful sensations are still real, even though they do not originate in the affected organ or in a part of the brain that would be common to all patients, these sensations being linked to the personal history of each patient.

2.2 - RECOMMENDED TREATMENT PROTOCOL

Clearly state the diagnosis

Once the diagnosis has been established, the doctor must state clearly “this is a psychosomatic symptom, anchored in your mind and your body”. The assurance in the formulation of this diagnosis is a key aspect of management; if there remains any room for uncertainty or doubt, this may arouse distrust in the patient, leading them on to a long and winding search for diagnosis that could last many years. These patients are often disconcerted by a diagnosis that seems to them to accord less value to their condition in comparison with “organic” diseases, which may delay individualised management while increasing the risk of depression. Some concrete examples may help the doctor to convince the patient, such as that of the painful phantom limb, in which pain is truly felt although the limb is no longer there, demonstrating the painful memory of the shock of loss. It is also possible to explain the affective and emotional dimension of pain, transmitted by the limbic system.

The doctor must endeavour to convince the patient to avoid self-examinations and topical treatments, avoiding oral interventions as far as possible (cosmetic braces, biopsies etc.), as these could become the subject of anxious fixations, and not to request further examinations. This approach reassures patients and it means that they let go of the idea that they have a rare condition of unknown origin. If the doctor takes this approach it also encourages quick and appropriate management, avoiding progression in which patients develop severe depression or chronic pain.

2.3 - EARLY AND HOLISTIC MANAGEMENT

Indication

The idea of treating the psychological aspect of the symptom may come from the patients themselves or from the doctor consulted (stomatologist, ENT, dentist, dermatologist specialised in pathologies of the oral mucosa, general practitioner, psychiatrist).

Psychoanalytic psychotherapy, based on our experience in a private practice, offers patients long-lasting relief. Other approaches exist (behavioural), and these have the advantage of being widely accepted in the medical world. Psychoanalytic psychotherapy, started from the onset of the patient’s problems, combined with a suitable anxiolytic or antidepressant medication, can in our experience offer the best results, in the form of a usual reduction by 30 to 70% of unpleasant sensations after 8 to 12 sessions. We use the evaluation scales recommended by ANAES (French health authority). Cases of complete remission have been reported in our practice, either after a few sessions or after a sufficiently long course of psychotherapy (over 18 months).

Psychoanalytic psychotherapy has the advantage, in comparison to other therapies and to psychotropic treatment, of acting not only on the symptoms but also on the causes, which together are known as “depressive predisposition” or “psychosomatic potential”. It enables the patient to no longer express discomfort through the body, but to develop autonomy, the capacity to find new solutions to move on in life. It also allows for both a shorter duration and a lower dosage of associated psychotropic drugs. It nonetheless demands that the patient should be really motivated to undertake this treatment founded on listening and self-expression.

An essential factor in the success of the therapeutic relationship is the confidence that the doctor has in the client. It is this level of confidence that will be transferred to the patient through the relationship.

Prescription

The doctor will assess the patient’s depression or anxiety and offer them an anxiolytic or antidepressant that is suitable for them, paying attention to the solution that will lead to greatest patient compliance in each individual case, compliance being an important factor for success.

Scientific studies and our observations allow us to state that a synergy between one of a number of “gentle” medical therapies and psychotherapy may be enough to stop an early or mild anxiety or depression from escalating. If these measures cannot be put in place for individual reasons, the doctor will prescribe a psychotropic medication using a treatment protocol that includes a weaning phase. This is because psychotropic drugs act on symptoms of anxiety and depression but do not treat the causes of the depression. If medication is taken for too long it could be an obstacle to the patient’s psychological reorganisation as brought about by analytical psychotherapy. In the group of imipramine antidepressants, clomipramine (Anafranil^®) (10, 25 and 75 mg tablets, usual dosage between 75 and 150 mg/day) is the reference antidepressant treatment, and experience has shown that it can produce good results in POP. An example regimen would consist of the clinician gradually initiating treatment with 25 - 50 mg/day taken at bedtime going up to 75 mg and sometimes 150 mg/day after several weeks. Amitriptyline (Laroxyl^®) (25 and 50 mg capsules or solution, usual dosage from 25 to 150 mg/day) is particularly practical to use as long as the usual contraindications are noted (for moderate cases, prescribe 2 - 15 drops at bedtime). If the patient cannot tolerate the side effects of these medications, in particular if they trigger a dry mouth or daytime somnolence, a non-tricyclic and less anxiolytic antidepressant may be substituted. Mianserin (Athymil^®), a non-tricyclic antidepressant and anxiolytic, has the advantage of a being able to be used as a monotherapy in view of its sedative effect.

Newer products offer the benefit of a simpler dosage regimen, as the required dosage can be administered in a single dose from the outset. Some of the SSRIs to be offered are setraline (Zoloft^®) (50 mg gel capsules, usual dosage 50 mg/day), paroxetine (Deroxat) (20 mg tablet, usual dosage 20 mg/day), and fluoxetine (Prozac^®) (20 mg gel capsules/solution, usual dosage 1 gel capsule/day). Milnacipran (Ixel^®)(25 and 50 mg gel capsules, usual dosage 200 mg/day) and venlafaxine (Effexor^®) (37.5 and 75 mg tablets) are also interesting because of their dual action on serotonin and norepinephrine with their roles in the physiology of anxiety and depression. Other newer antidepressants that could also be mentioned are escitalopram (Seroplex^®), mirtazapine (Norset^®) (which can lead to weight loss), and duloxetine (Cymbalta^®).

As the patient often presents signs of anxious mood, it can be useful to add an anxiolytic, such as a benzodiazepine. However, recent studies on the potentially dangerous side effects of benzodiazepines mean that these drugs must be used with care, and they are prescribed only if the patient’s condition requires it and for a short duration: bromazepam (lexomil^®) (1 mg tablet, usual dosage 1 mg/day in 4 doses) or alprazolam (Xanax^®) (0.25 and 0.50 mg tablets). Begin by prescribing ¼ to ½ a tablet in the evening for lexomil^® and ½ to 1 tablet per day for Xanax^® 0.25. These doses may then be doubled depending on the patient’s condition. Hydroxylzine (Atarax^®) (25 and 100 mg tablets, usual dosage one to four 0.25 mg tablets/day, preferably at bedtime due to the sleep-inducing effect) offers the advantage of not leading to dependence..

3 - EVALUATING TREATMENT

The treatment and the dosage will be evaluated for the first time after four weeks of treatment, and possibly adjusted depending on the result. When the patient’s condition has improved, the dose must be maintained over several weeks, and often several months.

At the end of the first six months to two years, the clinician must plan to gradually wean the patient off treatment. This must never be done suddenly, and it will be considered after several months of effective treatment.

4 - ABSTRACT

POP is a common disease seen by clinicians specialised in oral or dental disorders. They consist in more or less burning or pricking sensations in the tongue or other parts of the mouth, which cause discomfort owing essentially to their persistence and daily occurrence.. They have no objectively identifiable organic cause. Patients who experience these sensations may complain of disabling pains. They are often associated with salivary and gustatory problems, forming together a syndrome that is currently known as stomatodynia or burning mouth syndrome. The authors emphasise the fact that problems of anxiety or depression are constantly present, and that they could be integrated as a fourth element and the most likely cause of the syndrome, The reason for which they propose the term psychogenic oral paresthesia (POP). Secondary oral paresthesia due to other local or systemic factors should be considered as a differential diagnosis from POP. Having analytically listened to patients, we propose the idea that very often POP is the expression of "masked (or hidden) depression", i.e. an inability to mentally progress through separation, instead returning to an old and traumatic experience of separation. Early and holistic management is essential in order to, on the one hand, avoid the patient progressing to living with chronic pain and/or severe depression, and on the other, to undermine the patient’s belief that they have a “rare illness of unknown origin”, as maintaining this belief leads to avoidance of appropriate management. The treatment involves psychotherapy conducted by a therapist with analytical training combined with an anxiolytic or antidepressant drug that is suitable for the individual patient and prescribed by the doctor.