Guide to Pain Management in Low-Resource Settings

Glossopharyngeal nerve
Neuralgia with pain in the throat that increases with 
swallowing.
Intercostal nerves
Pain starting at the back of the chest wall and shooting 
along the distribution of the corresponding intercostal 
nerve, producing a feeling of chest tightness and possi-
bly, if left-sided, confused with myocardial infarction.
Lumbar and sacral plexuses and nerves
Pain in the genital tract (in males and females) may be 
confused with the diagnosis of genital herpes simplex. 
However, the fact that PHN is more painful and not 
usually recurrent like simplex virus should lead to the 
right diagnosis.
What observations are typically made                
in the examination of the patient?
Observed signs:
• Th
  e skin is discolored, with areas of hyper- and 
hypopigmentation called “café au lait” skin.
Sex
Males and females can develop herpes zoster.
Race
Races with darker skin (Indian, African, and Latin 
American) are more resistant than those with lighter 
skin (Caucasian). Th
  e reason is unknown.
Social and psychological factors
Th
  e incidence of shingles is associated with exposure to 
severe stressful conditions such as war, loss of a job, or 
the death of close family members.
What symptoms are helpful in diagnosis of 
shingles and postherpetic neuralgia?
Th
  e clinician should know the symptoms of acute her-
pes zoster and the diff erent stages of disease, which typ-
ically are:
•  Sharp and jabbing, burning, or deep and aching 
pain
• Extreme sensitivity to touch and temperature 
changes (symptoms 1 and 2 could be misdiag-
nosed as myositis, pleurisy, or ischemic heart dis-
ease)
•  Itching and numbness (which may be misdiag-
nosed as skin allergy)
Age
Possible Cause
0–18 years 
AIDS/HIV, leukemia, Hodgkin’s disease, tubercu-
losis
20–40 
years
Steroid therapy, AIDS/HIV, diabetes mellitus, major 
operations (organ transplant), infection (viral, bac-
terial, fungal, or parasitic)
60–80 
years
Malignant conditions should be the fi rst possibility, 
and most of the above-mentioned factors could also 
be present

Management of Postherpetic Neuralgia
185
• Severe pain-like electric shock sensations are 
evoked on gently touching or brushing the af-
fected area of skin with a fi ne cotton fi lament or 
horsehair brush.
•  Most of the patients are in a depressed or ex-
hausted state due to lack of sleep.
• Th
  e degree of postherpetic scarring of the skin 
is an indicator of the prognosis of the neuralgia. 
Severe scarring of the skin is associated with se-
vere nerve destruction (demyelination) and cor-
responding severe damage of the posterior dor-
sal horn neurons and nerve root ganglion. Such 
patients have a higher risk of severe, long-lasting 
postherpetic neuralgia, which is diffi
  cult to treat.
What further investigations could help     
ensure the correct diagnosis or exclude    
certain pathologies?
•  Full blood screen (screening for signs or evidence 
of chronic infection, e.g., AIDS/HIV).
•  Fasting blood sugar and blood sugar 2 hours after 
a meal as a screen for diabetes.
•  Plain X-ray to screen for bone cancer or fractures.
•  CT and MRI if available to screen for soft-tissue 
malignant masses.
• Coagulation tests, in case invasive therapy is 
planned.
PHN is a painful condition and may 
impair the quality of life of aff ected 
patients. Can it really become    
life-threatening?
In the acute stage of herpes zoster, most patients prefer 
to take off  their clothes due to increased touch sensitiv-
ity (allodynia) of the skin, which could make them sus-
ceptible to pneumonia, especially in the winter season.
A psychological reaction is common in PHN; 
most patients are elderly and lonely, and they may be 
suff ering from diff erent degrees of depression, which 
may lead to suicide. Also, the high level of pain might 
pose a direct threat to the patient due to marked sym-
pathetic stimulation, which can lead to tachycardia or 
hypertension, or both, and may result in “pain-induced 
stress.” A patient with a comorbidity, such as ischemic 
heart disease, could be at an increased risk for myocar-
dial or cerebrovascular complications.
Aff ection of cranial nerve VIII (the vestibulo-
cochlear nerve) may result in severe abnormal sound 
sensations with subsequent lack of sleep, followed by 
depression or even suicidal attempts.
Another complication of PHN may be second-
ary changes of the musculoskeletal system due to the 
patient’s attempts at trying to fi x or immobilize the af-
fected body part, such as the shoulder, elbow, wrist, 
knee joints or fi ngers. At an older age, long-term im-
mobility of such joints will result in severe painful stiff -
ness. Early and very gentle physiotherapy is highly rec-
ommended in such conditions. Another consequence of 
immobility is disuse atrophy and increased osteoporo-
sis, especially in elderly patients. Th
  ese patients will be 
more liable to have bone fractures in response to simple 
trauma. Th
  e highest incidence of bone fractures is to 
be expected during physiotherapy by an inexperienced 
physiotherapist.
In conclusion, although herpes zoster and PHN 
are not considered life-threatening conditions, second-
ary changes may impair the quality of life, increase mor-
bidity, and may have lethal consequences in some pa-
tients.  Th
  erefore the treatment of these pain syndromes 
involves more than just relieving pain.
What are the principles                     
of treatment?
Th
  e best approach is to prevent herpes zoster infection. 
A vaccination against herpes zoster was only introduced 
recently (Zostavax, approved by the U.S. Food and Drug 
Administration for patients at risk over the age of 60 
years) and is not widely available. Th
 erapeutic eff orts 
still have to concentrate on treatment of the acute infec-
tion. Unfortunately, even adequate acute treatment does 
not change the course of PHN, although it does dimin-
ish the acute pain and the risk of secondary complica-
tions from the herpes zoster infection.
What can be done for patients with herpes 
zoster infection at an early stage?
With proper and early diagnosis of herpes zoster, an-
tiviral drugs should be used as early as possible, and 
within 72 hours from appearance of the vesicles, and 
should be administered to the patient for 5 days. Th
 e 
standard drug is acyclovir at a dose of 200 mg q.i.d. 
Older patients and those with risk factors but without 
any indication of generalized infection may addition-
ally receive steroids. Steroids should only be used con-
comitantly with an antiviral drug to avoid a fl are-up of 
the infection. To avoid dendritic ulcers in ophthalmic 

186
Maged El-Ansary
herpes zoster, special ointments of acyclovir should be 
used locally, if available. In countries with limited re-
sources, acyclovir will be unavailable or unaff ordable 
for most patients, but this does not necessarily mean a 
worse prognosis regarding PHN compared to patients 
taking acyclovir.
Antibiotic ointments should be used if second-
ary infections start to appear. Sometimes, potassium 
permanganate can be used as topical antiseptic, and cal-
amine lotion for pruritis. A simple and cheap local ther-
apy is the topical application of crushed aspirin tablets 
mixed either with ether or an antiseptic solution (1000 
mg of aspirin mixed in 20 cc of solution).
Another local remedy, which may be repeat-
ed, is subcutaneous injection of local anesthetics as a 
field block in the painful area. All available local an-
esthetics maybe used, but daily maximum doses have 
to be observed.
Antiviral, steroids, and topical medications may 
reduce the symptoms of acute herpes zoster but 
are often insuffi
  cient to control pain. What are 
the best analgesics to use?
As a general rule in pain management, drugs have to 
be titrated gradually against pain until eff ective.  Since 
many of the aff ected patients are old or have a comor-
bidity, compromising their general condition, it is ad-
vised to “start low and go slow.”
Herpes zoster involves infl ammation of the 
tissue around the nerve root. Anti-infl ammatory  an-
algesics such as ibuprofen or diclofenac are indicated 
as drugs of fi rst choice. If there are contraindications, 
such as steroid medication, dehydration, a history of 
gastric ulcers, or old age with impaired renal function, 
paracetamol/acetaminophen (1 g q.i.d.) or dipyrone (at 
the same dose) is indicated.
If these drugs prove to be inadequate, guidelines 
for the treatment of neuropathic pain nowadays rec-
ommend coanalgesics. If these drugs are not available, 
opioid analgesics (usually recommended as second-line 
drugs after the use of coanalgesics) should be used. In 
herpes zoster pain, it is not necessary to use “strong” 
opioids, for which there might be governmental restric-
tions. Tramadol, a weak opioid analgesics, which due to 
its specifi c mode of action is not regarded as an opioid 
in many countries, and is therefore unrestricted, will be 
suffi
  cient for most patients. Tramadol should be started 
with 50-mg tablets b.i.d. and may be increased in dose 
daily by 50–100 mg until suffi
  cient analgesia is achieved. 
Th
  e maximum dose is 150 mg q.i.d., but most patients 
will do fi ne with 50–100 mg q.i.d. If slow-release for-
mulations are available, the daily dose has to be divided 
(b.i.d. to t.i.d.). Th
  e typical side eff ects of nausea and 
vomiting should be less frequent with the slow-release 
formulation. Alternatives to tramadol are codeine and 
dextropropoxyphene.
If I have coanalgesics available, how do 
I  choose the right one for my patient                 
with  acute herpes zoster?
Generally speaking, for herpes zoster, coanalgesics 
should be chosen according to the guidelines published 
on neuropathic pain, since acute herpes zoster causes 
mostly neuropathic pain. Th
 erefore, the drug of fi rst 
choice would be either amitriptyline or gabapentin (or 
a comparable alternative such as nortriptyline or prega-
balin). Th
  e decision between a tricyclic antidepressant 
and an anticonvulsant should be made according to the 
typical side-eff ect  profi le. Patients with liver diseases, 
reduced general condition, heart arrhythmias, consti-
pation, or glaucoma should receive gabapentin or pre-
gabalin. Th
  ese are presumably weaker analgesics, but 
they have the great advantage that no serious side ef-
fects are to be expected. Also, no ECG or blood tests 
have to be performed. Both drug families have their 
best effi
  cacy against constant burning pain, but they 
may be insuffi
  cient for attacks of shooting or electrical 
pain. For other drug options, refer to the appropriate 
chapters in this manual.
I have tried local and systemic therapeutic 
options, but the patient still has excruciating 
pain. Are there any other choices?
Unfortunately, there is no “wonder drug” available. If 
the above therapeutic strategies fail, it might be worth-
while to send the patient to a referral hospital that has 
dedicated pain therapists. Otherwise, strong opioids 
would be an alternative, if available. If none of these al-
ternatives apply, guiding the patient with tender loving 
care and explaining the usual limited time of intense 
pain are suggested. Never tell a patient that you can’t do 
anything for him.
So, what can an experienced pain therapist or 
“regular” anesthesiologist off er the patient?
Th
 e therapy of choice in such incidences is regional 
anesthesia using epidural catheters. Th
 is  technique 
is usually applied for major surgery or certain surgical 

Management of Postherpetic Neuralgia
187
procedures, when no general anesthesia is possible or 
necessary. Th
  ese epidural catheters may be inserted at 
almost all levels (cervical, thoracic, or lumbosacral). If 
the head or upper neck region is aff ected, then epidu-
ral analgesia will not succeed. Th
  ere is no evidence that 
regional anesthesia shortens the course of acute zoster 
or reduces the chances for PHN. Th
  erefore, such an in-
vasive treatment would only be justifi ed with refractory 
excruciating pain, in order to control pain for a limited 
time period until the spontaneous reduction of pain oc-
curs.
Regional sympathetic chain blocks, for exam-
ple at the stellate ganglion or at the thoracic or lumbar 
sympathetic chain, are usually only possible as one-time 
injections, and therefore do not control pain for more 
than a couple of hours. Th
  ese techniques have their use 
in PHN at a specialized pain clinic when there is evi-
dence that the pain is sympathetically maintained.
What to do when the acute herpes zoster has 
healed and postherpetic neuralgia persists with 
intolerable pain?
Clinical experience shows that successful treatment 
of established PHN is diffi
  cult. Th
  e main reason is the 
considerable nerve damage present and the unlikeli-
hood that repair mechanisms will restore the nerve 
roots. Th
  erefore, the patient must be instructed not to 
have expectations that are too high. Th
  e goal of therapy 
is, therefore not “healing” with complete recovery of the 
sensory defi cit and complete disappearance of pain, but 
only the reduction of pain, and usually 50% reduction is 
seen as a “successful treatment.”
What drugs should be chosen for postherpetic 
neuralgia?
In general, the drugs of fi rst choice for PHN are the 
same as for treatment of pain in acute herpes zoster. 
Th
  erefore, the fi rst thing to do is to increase the dose of 
the tricyclic antidepressant (e.g., amitriptyline 25 mg at 
night) or the anticonvulsant (e.g., gabapentin 100 mg at 
night) or the weak opioid (e.g., tramadol) in a stepwise 
fashion, trying to reach the goal of 50% pain reduction. 
If this is not possible due to side eff ects, the tricyclic 
antidepressant or the anticonvulsant should be com-
bined with a weak opioid. Th
  e next step would be to try 
a strong opioid, such as morphine, to replace tramadol, 
titrating the morphine until pain reduction is achieved. 
If attacks of pain, such as shooting or electrical pain, oc-
cur, gabapentin or pregabalin should be replaced by a 
sodium-channel-blocking anticonvulsant such as carba-
mazepine, which often is more successful in this specifi c 
type of neuropathic pain.
If the standard drugs are not reducing the 
pain adequately or cannot be tolerated due to 
lasting side eff ects, what options are available, 
especially with allodynia?
When standard drugs do not reduce the pain adequate-
ly, especially with allodynia (pain in response to light 
touch in the aff ected dermatome), local topical therapy 
options should be tried. A very good option would be 
topical local anesthetics, such as EMLA cream (which 
might be available from the anesthesia department), 
which can be very eff ective if used 3–4 times a day.
Lidocaine patches are small, bandage-like 
patches that contain the topical pain-relieving medica-
tion, lidocaine. Th
  e patches, available by prescription, 
must be applied directly to painful skin to deliver relief 
for up to 12 hours (preferably at night). Patches contain-
ing lidocaine can also be used on the face, taking care to 
avoid mucus membranes including the eyes, nose, and 
mouth. Th
  e advantage of EMLA cream and lidocaine 
patches is that the local anesthetic they contain is only 
absorbed into the bloodstream in very low quantities, 
therefore avoiding any systemic side eff ects, but possibly 
causing local skin irritation.
EMLA cream and lidocaine patches are expen-
sive and are not yet available in most of the develop-
ing countries. A cheap and available alternative is the 
local use of 5% lidocaine jelly. A thin fi lm, spread over 
the painful area of skin and covered with a fi ne sheet of 
polyethylene for 1 hour, eff ective in most patients. It is 
important to remove any jelly from the patient’s clothes.
What other options would I have, where I 
have the possibility of referring the patient 
to a colleague experienced in invasive pain 
procedures?
Patients with pain unresponsive to systemic drug 
treatment could receive repeated nerve blocks of the 
corresponding areas of pain, such as the intercostal 
nerves. Apart from targeting the peripheral nerves, 
the epidural or intrathecal space may be used to ap-
ply analgesics. Epidural catheters, using, for example, 
5 mL bupivacaine 0.125%, morphine 2 mg, and cloni-
dine 35 μg/12 hours, are eff ective for control of pain. 
Unfortunately, this catheter technique is not able to re-
duce pain in the long term. Th
  erefore, after cessation 

188
Maged El-Ansary
of the catheter analgesia, the pain usually resumes and 
remains. Even in major pain management centers, this 
technique is only used to control acute pain exacerba-
tions, since long-term treatment would imply surgical 
implantation of a catheter (intrathecally). Implanted 
catheters need highly specialized care and tend to fail 
frequently, and therefore they are indicated only in very 
special circumstances. Most conditions will respond af-
ter 3–6 months of treatment.
Another rather simple option is counterirrita-
tion of the aff ected dermatome with transcutaneous 
electrical nerve stimulation (TENS). With a small and 
simple device, an electrical current is applied to skin ar-
eas with a certain current and frequency, producing a 
nonpainful dysesthesia. With this treatment, the patient 
may have short-term or even long-term pain reduction. 
Th
  e mechanism for TENS is the blockade of pain trans-
mission through the nerve fi bers responsible for touch 
(A-beta fi bers). Although the mechanism necessary to 
apply the electrical stimulation is simple, unfortunately 
TENS devices available on the market are expensive, 
and therefore should be given to patients on a rental ba-
sis. Some patients respond well, and others not, but be-
cause TENS is simple and inexpensive, it could be used 
in developing countries and also by the non-pain spe-
cialist, such as a general practitioner. It cannot be used 
on the head or neck or in pregnant women.
Th
  e successful use of TENS helped to develop 
implantable electrodes for direct stimulation of the spi-
nal cord, for a therapy known as spinal cord stimulation 
(SCS). Even in high-resource countries this technique 
is only used in selected patients with PHN. Th
 e same 
applies to cryoanalgesia and radiofrequency. All these 
techniques are outside the scope of this manual because 
they are highly sophisticated, very expensive, and re-
quire lengthy experience in pain management.
Another simpler option, which might be used 
by a therapist experienced in block techniques, most 
likely an anesthesiologist, is ablation of nerves (e.g., the 
intercostal nerves) by phenol in water (6%) or alcohol 
(60%). Th
  is treatment is eff ective for prolonged periods 
of time but is not permanent. Th
  erefore, it is only to 
be used in cases of PHN associated with cancer where 
life expectancy is less than 6 months. With careful use 
of the technique, the complication rate for this patient 
group can be acceptable. Th
  e complication rate depends 
on the site of ablation.
Pearls of wisdom
•  Postherpetic neuralgia is a multifactorial problem.
•  Prevention, early diagnosis. and aggressive treat-
ment are of great importance.
• Postherpetic neuralgia is an alarming disease, 
sometimes hiding a more complicated health 
problem, and therefore diff erential diagnosis is 
crucial. Management of PHN should go hand in 
hand with a search for other pathology respon-
sible for attenuating the immune-defense system.
• Diff erent modalities are to be used to treat the 
condition because most of the time no single line 
of treatment is eff ective.
•  Once PHN is established, it has some complica-
tions of its own. Th
  ese will range from lack of 
sleep, joint stiff ness, secondary infections, and 
vascular strokes up to suicide attempts. Th
 us, 
adequate diagnosis and treatment of acute her-
pes zoster and postherpetic neuralgia should be 
expected—and to a certain extent this is possible 
in most patients—from the caring physician or 
other health care worker.
References
[1]  Baron R, Saguer M. Mechanical allodynia in postherpetic neuralgia: 
evidence for central mechanisms depending on nociceptive C-fi ber de-
generation. Neurology 1995;45(12 Suppl 8):S63–5.
[2]  Haanpää M, Dastidar P, Weinberg A, Levin M, Miettinen A, Lapinlam-
pi A, Laippala P, Nurmikko T. CSF and MRI fi ndings in patients with 
acute herpes zoster. Neurology 1998;51:1405–11.
[3]  He L, Zhang D, Zhou M, Zhu C. Corticosteroids for preventing 
postherpetic neuralgia. Cochrane Database Syst Rev 2008;1:CD005582.
[4]  Nurmikko T. Clinical features and pathophysiologic mechanisms of 
postherpetic neuralgia. Neurology 1995;45(12 Suppl 8):S54–5.
[5]  Rice AS, Maton S. Gabapentin in postherpetic neuralgia: a randomised, 
double blind, placebo controlled study. Pain 2001;94: 215–22.

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Guide to Pain Management in Low-Resource Settings, edited by Andreas Kopf and Nilesh B. Patel. IASP, Seattle, © 2010. All rights reserved. Th
  is material may be used for educational 
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