Diagnosis and medical treatment of neuropathic pain in leprosy

ABSTRACT Objective: to identify the difficulties in diagnosing and treating neuropathic pain caused by leprosy and to understand the main characteristics of this situation. Methods: 85 patients were treated in outpatient units with reference to leprosy and the accompanying pain. We used a questionnaire known as the Douleur Neuropathic 4 test and we conducted detailed neurological exams. As a result, 42 patients were excluded from the study for not having proved their pain. Results: Out of the 37 patients that experienced pain, 22 (59.5%) had neuropathic pain (or a mixture of this pain and their existing pain) and of these 90.8% considered this pain to be moderate or severe. 81.8% of the sample suffered with this pain for more than 6 months. Only 12 (54.5%) of the patients had been diagnosed with neuropathic pain and in almost half of these cases, this pain had not been diagnosed. With reference to medical treatment (n=12) for neuropathic pain, 5 (41.6%) responded that they became better. For the other 7 (58.4%) there were no changes in relation to the pain or in some cases the pain worsened in comparison to their previous state. Statistical analysis comparing improvements in relation to the pain amongst the patients that were treated (n=12) and those that were not, showed significant differences (value p=0.020). Conclusion: we noted difficulties in diagnosing neuropathic pain for leprosy in that almost half of the patients that were studied had not had their pain diagnosed. We attributed this to some factors such as the non-adoption of the appropriate protocols which led to inadequate diagnosis and treatment that overlooked the true picture.


Introduction
The presence of pain is a common characteristic in patients with leprosy. It is responsible for physical and psychological pain (1). The cause of the pain is connected to secondary nociceptive stimulus and tissue inflammation which is often triggers off episodes of immune activation (reverse reaction and erythema nodosoum leprosum). Alternatively there is a neuropathic cause that is secondary to the damage which causes a complete lack of functioning of the nervous system (2).
The International Association for the Study into Pain (IASP) defines the pain as being caused by lesions or somatosensory nervous system diseases. Neuropathic pain is a type of pain that has been ignored in the treatment of those with leprosy (3)(4). For a long time it was attributed to inflammatory processes, or even the process of neural compression -nociceptive pain, being responsible for the entire pain for this group of patients.
Erroneous diagnosis ended up being prejudicial for the patients that were not treated appropriately as well as causing comorbidities such as gastric problems, osteoporosis, neuropathy amongst others. This occurred due to the excessive use of anti-inflammatories particularly corticosteroids. This with analgesics, made up the few tools that health practitioners had.  indicating that they took part of the own free will. Then  After having defined the case as stemming from neuropathy we used the Numeric Rating Scale -NRS to understand better the intensity and the area of the pain (the process is known as Pain Drawing -PD) (12)(13).
Deformities were evaluated using the WHO criteria: Level zero -no deformity, Level 1 -loss of sensitivity in the hands and feet or Level 2 -visible motor deformity, including lagophthalmos and the gripping of fingers and contractures and/or ulcers on the hands and feet(14).
In Figure 2 the inclusion criteria used for the patients whose pain stemmed from neuropathy, can be seen.
We opted to exclude patients that were diagnosed with diabetes Mellitus and/or alcoholism so there would be no confusion regarding possible diagnosis of neuropathy and the aforementioned diseases being other possible causes.  where appropriate. We considered the limit of statistical significance to be the value of p≤0,05.

Results
Out of the 85 patients who had leprosy that we studied, 37 (43.5%) were in a painful nociceptive state and/or were neuropathic and 48 (56.5%) were excluded for not having complained of pain or for just having referred to it in the past.
After having applied the questions to diagnose the cause of the pain to be neuropathic in the 37 patients who complained of pain, we noted that 12 of them did not match up to the inclusion criteria ( Figure 2) and were thus excluded. The remaining 22 patients that complained of neuropathic pain or a mixture of other pains represented 25.9% of the total population that was analyzed (n=85) and they were the main focus of this study.

General Characteristics
The following are details on the profile of those affected by neuropathic pain related to leprosy in our study: 14 (63.7%) were women and their age varied from 24 to 66 years old, with an average age of 51 (dp±10,78).
Fifteen (68.1%) patients that were affected showed a form of MB. We noted that for those who had been diagnosed for a long period of time there was a greater frequency of neuropathic pain. 14 (63.7%) had known about the disease for more than 5 years with 11 (50%) having undergone PQT for more than 5 years. The existence or previous existence of a reactionary state did not show that this in itself had any bearing on the neuropathic pain.
The clinical characteristics are shown below in Table 1.

Diagnosis and Treatment
Out  Table 2).  There were improvements for the patients that were treated in comparison to those that were not with medication. The information was obtained when they were questioned (n=12), (valor de p=0,020). There were no significant differences in relation to the intensity of the pain and the DN4 points between patients that were treated for neuropathic pain (n=12) and those that were not (n=10). (Table 3). respectively (1,15).

Discussion
This is an important cause of the patients suffering.
90.8% stated that the pain was moderate and/or severe and 81.8% stated that they suffered for longer than six months. Nearly half of the cases studied did not have a diagnosis (45.5%). This finding highlights the fact that neuropathic pain cause by leprosy is not being picked up by health care teams. They spend most of their time looking for new cases of the disease and using polychemotherapy for existing cases. They deal with reactionary episodes and the prevention of deformities as well as the controlling communicants (4,16) . The use of medications for treatment of neuropathic pain caused by leprosy has not been fully tested.

Random and control tests are needed for class I and II
medications which are not currently covered by medical journals. A good understanding of these therapies can alleviate symptoms and prevent neuropathic lesions for patients with leprosy (16)(17)(18) . A revision of the studies on treatment of various causes of neuropathic pain has included, in the majority of cases, ill people with severe polyneuropathy diabetes and postherpetic neuralgia (19) .
Medication treatment for neuropathic pain (as recommended by AMB) ought to commence with the application of low doses and then it can be increased on a gradual basis where the pain persists. The herpetic and renal functions of the body need to be monitored.
Patients ought to be told of possible side effects.
Medication that is cost effective and produces benefits should be sought out (20)(21) .
The Brazilian Government provides some free difficulties. This is because the results showed significant improvements in the pain compared to those that were not treated. During the study, all of the patients that had not been diagnosed with neuropathic pain were given information about the illness. They were then given medication and were monitored by specialist in chronic pain.

Conclusion
We noted difficulties in diagnosing neuropathic pain for those with leprosy in that almost half of the patients that were studied had not had their pain diagnosed. One of the main reasons for this is because medical staff are not using, on a routine basis, an adequate protocol which would allow them to investigate and effectively diagnosis neuropathic pain. Complications and prolonged suffering is caused by misdiagnosis and inadequate treatment.
Neuropathic pain in patients that had been treated with leprosy reached 90.1% of cases. They stated that they had to deal with moderate and severe pain for more than six months. Therefore neuropathic pain for those with leprosy is an important cause for suffering.
The results show significant improvements in the symptoms for those that received treatment in comparison to those that did not. The reasons can be given for those that stated to be the same or who became worse after the therapy include: the high degree of side effects, insufficient doses of the medication used, and the non-use of polytherapy in cases in which the therapeutic responses to one drug was unsatisfactory.
We therefore conclude that treatment through the use of medication for neuropathic pain ought to be introduced, despite there not being many systematic and methodological studies in this area. This would go a long way in reducing human suffering.