OJHAS Vol. 9, Issue 4:
Congenital Insensitivity to Pain
Praveen Kumar B, Senior
Sudhakar S, Senior
Prabhat MPV, Associate Professor,
of Oral Medicine & Radiology, St.
Joseph Dental College, Duggirala,
Eluru (Andhra Pradesh) Ė 534003, India.
Address For Correspondence
of Oral Medicine & Radiology,
Eluru (Andhra Pradesh) Ė 534003, India.
Praveen Kumar B, Sudhakar S, Prabhat MPV. Congenital
Insensitivity to Pain. Online J Health Allied Scs.
Submitted: Aug 13, 2010; Suggested revision: Oct 4, 2010;
Revised: Oct 26, 2010; Accepted: Nov 3, 2010; Published: Jan 20, 2011
Insensitivity to Pain belongs to the family of Hereditary Sensory and
Autonomic Neuropathies (HSAN). It is a rare disorder of unknown etiology
associated with loss of pain sensation. Cognition and sensation is otherwise normal and there is no
detectable physical abnormality. We report a case of Congenital Insensitivity
to Pain in a 3 year old female child.
Key Words: Congenital; Pain; Insensitivity; Nerve; HSAN
Pain is an
unpleasant sensory and emotional experience associated with actual or
potential tissue damage, or described in terms of such damage.(1)
Most of us from the day we are born have this intuitive notion about
pain or known to be aware of it by learning from our experiences. Imagine
a life without pain, we will never feel a headache, or a toothache,
or even a broken arm. This condition is called Congenital Insensitivity
to Pain. Most people would think it would be great to live without pain,
but one should understand, pain is an indication to our brain that our
body needs something.
A 3 years old
female patient reported to Department of Oral Medicine and Radiology
with a complaint of missing lower front teeth and wound over her chin
(Fig 1). Patientís mother gave a history of trauma to her daughterís
chin 5-days back. Following which she noticed the wound and missing
lower front teeth. Patientís mother also noticed bleeding from the
lower front teeth region which subsided spontaneously after applying
topical country medication. There was no history of pain, parasthesia,
difficulty in opening mouth, speech and mastication.
history of the patient revealed that she had frequent history of trauma either
unknown or self mutilated. The recent history was that of a trauma to her
fingers 20 days ago and did not show any signs of discomfort. The child was
generally considered normal as she rarely cries.
revealed that she was a product of consanguineous marriage and did not have any
complaint at the time of birth and her other sibling was normal.
examination revealed a well oriented, partly cooperative, moderately
built and nourished child with all her vital signs within satisfactory
limits. Patient presented with multiple scars and wound over her left
thumb, middle and index finger nails with shortening of fingers (Fig
2 & 3). A solitary oval shaped ulcer ranging 2x2cms in size was
noted over the sole of right toe (Fig 4). The borders were well defined
with an erythematosus base. It was nontender on palpation.
examination showed presence of abraded wound over the symphysis region
ranging 3x3cms in size (Fig 5). The surface appeared erythematous and was non
tender on palpation. The facial bones appeared normal. Intra oral examination
revealed missing 71, 72, 73, 81, 82 and mobility of 61. Decayed 51, 52, 54, 55,
64, 65, 74, 75, 84 and 85 were noted.
Based on the
history and clinical findings a provisional diagnosis of avulsed 71,
72, 73, 81, 82; traumatic erosion over the chin and congenital insensitivity
to pain were considered with the following differential diagnoses: Lesch-Nyhan
syndrome, familial dysautonomia and familial amyloidosis.
subjected to radiological investigations, to rule out any fractures
involving the facial skeleton. As she was uncooperative for Orthopantamogram
(OPG), it was decided to take a Posteroanterior (PA) view of skull with
the patients head stabilized by her attender. The PA view did not show any
pathological changes (Fig 6).
Fig 6: Posterioanterior view of skull
Then the patient
was referred to a general physician and neurologist. The patient
was tested for measurement of pain intensity, hot and cold. The response
was noted in a visual analog scale. The testing materials included a
pin (of varying diameter- which was pricked on the sole of the feet),
ice cubes and hot instrument. Patient responded immediately to hot and
cold and for tactile sensation but not for pain. Sensory examinations
including light torch, proprioception and vibration were intact. Deep tendon and
corneal reflexes were present. There were no autonomic disturbances Ė she
sweated normally and produced tears. The uric acid levels were normal.
clinical and investigatory findings confirmed our diagnosis of congenital
insensitivity to pain.
parents and relatives were educated and cautioned about the condition.
For the traumatic erosion- topical antibacterial application thrice
daily (to prevent secondary infection) was advised and the patient was
referred to department of pedodontics for further dental management
and complete dental rehabilitation.
insensitivity to pain is a rare, autosomal recessive sensory neuropathy first
reported by Dearborn in 1932.(2) The disorder is characterized by absence of
reaction to painful stimuli, self-mutilating behavior. It is diagnosed early in
the childhood, as the affected child rarely cry of pain.
There are atleast
two common forms of congenital insensitivity to pain - Congenital insensitivity
to pain (HSAN - V) and congenital insensitivity to pain with anhidrosis
(HSAN - IV). Our case falls under the former category which is also
called as Congenital analgia or Congenital analgesia, congenital asymbolia
and even some prefer the term indifference instead of insensitivity.(3)
The type V is characterized by disorder in pain perception with no other
neurologic deficit, whereas HSAN Ė IV first reported by Nishida in 1951, is a
severe form which is characterized by disorders of pain perception and
The cause for
the disorder is not clear. There are various studies available in the
literature concern to CIPA, while studies related to congenital insensitivity
to pain are meager in the literature. There are many questions and assumptions
prevail regarding this condition. More recently, a study claims mutation
in the Nav1.7 encoded by the SCN9A gene located on the
chromosome 2q24.3 causes inability to experience pain.(5)
insensitivity to pain is an Autosomal recessive disorder with no ethnic
distribution. As seen in our case half of the cases are reported in
children born to consanguineous marriages.(6) The clinical features
of congenital insensitivity to pain vary markedly. The insensitivity
to pain is profound and may lead to repeated trauma and self-mutilation
as noted in the present case. An additional finding that may be noted
in these patients may include fractures that are slow to heal and frequently
go on to develop osteomyelitis and charcot joints.(7)
congenital insensitivity to pain should be done with atmost caution
as the clinical findings can resemble CIPA, which is a severe entity.
In association with pain the cardinal feature of CIPA is absent or markedly
decreased sweating causing episodic fevers and extreme hyperpyrexia
which is usually the earliest sign. Anhidrosis also contributes to the
thick and calloused appearance of the skin with lichenification of palms,
dystrophic nails, and areas of hypotrichosis on the scalp.(8) The individuals
affected with CIPA usually do not live past 3 years of age; if they
make it many do not past 25 years. The reason behind this is probably
due to anhidrosis leading to recurrent fevers that are unexplained and
can be fatal due to hyperthermia. Patients who survive their infant
years have a high chance of acquiring mental retardation. This may be
due to the fact that higher the body temperature goes the more harmful
bacteria and virus attacks can occur leading to swelling of blood vessels
causing aneurysms, all of which a CIPA patient will not even feel.
The other condition
that can resemble CIP is familial dysautonomia (Riley- Day syndrome).
The clinical features include absence of pain, lacrimation and fungiform
papillae. The condition also comprise of postural hypotension, hyperhidrosis,
nystagmus, poor muscle tone, co-ordination, and lack of reflexes.(3) Apart from
insensitivity to pain, the present case did not have any other features.
behavior can also be a part of Lesch-Nyhan syndrome, which is a rare,
inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine
phosphoribosyltransferase (HPRT). The diagnosis of Lesch-Nyhan
syndrome is based initially on the self-mutilating behaviors that begin
in the second year of life.(9) In some cases the first symptom is related
to overproduction of uric acid; the parents notice "orange sand"
in the child's diapers. The "sand" is actually crystals of
uric acid tinged with blood.(10) Abnormal high uric acid levels can
cause sodium urate crystals to form in the joints, kidneys, central
nervous system leading to gout-like swelling in the joints, failure
to crawl and walk at the usual ages. Measuring the amount of uric acid
in a person's blood or urine can be helpful in diagnosis of Lesch-Nyhan
syndrome. The present case did not have any aforementioned symptoms and the uric
acid level was normal.
of familial amyloidosis should also be considered while evaluating CIP, as
affected patientís present with preferential loss of pain. However, this
neuropathy can be readily differentiated as these patients pose loss of other
types of sensations and the tendon reflexes.(3)
and clinical findings of CIP usually leads to diagnosis. Neurological
studies such as electroencephalogram, cerebrospinal fluid, and sensory
and motor nerve conduction studies were tried and found normal in majority
of patients.(11) When a nerve is biopsied, the histological findings
may include a complete absence of non-myelinated and small myelinated nerve
fibers in the dorsal root ganglia.(12)
There is no
single gold standard treatment available for this condition. Reports
suggest naloxone and naltrexone can be used to reverse the analgesia.(6)
The above treatment option however lacks evidence and further support. Hence,
most treatments are narrow down to other associated conditions.
encounter such patients should bear in mind, that although they lack
the sensation of pain some may have tactile hyperesthesia. Hence anesthesia
is needed to reduce the apprehension, for relaxation of the muscle thereby
to avoid any accidental fractures.
insensitivity to pain is a rare group of neuropathic disorder. The varied
manifestations, the lack of validate investigation and treatment modalities
make it a distinctive entity. This necessitates the oral physician to
be cognizable with it and ample steps should be taken to reduce the
paranoia and post traumatic complications associated with it.
- Merskey H, Bogduk
N, editors. Classification of chronic pain, Task Force on Taxonomy,
International Association for the Study of Pain. 2nd ed.
Seattle: IASP Press: 1994. p. 210-213.
- Cox JJ et al.
An SCN9A channelopathy causes congenital inability to experience pain.
- Unknown author.
Insensitivity to pain. BMJ 1973;27:187-188.
- Nishida G. Congenital
Anhidrosis. Saishin Igaku (Japan) 1951;6:1100-1104.
- Drenth JPH, Waxman
SG. Mutations in sodium-channel gene SCN9A cause a spectrum
of human genetic pain disorders. J. Clin. Invest 2007;117(12):3603-3609.
- Protheroe SM. Congenital
insensitivity to pain. Journal of the Royal Society of Medicine 1991;84:558-559.
- Felicia B, Max J.
Inherited Autonomic Neuropathies. Seminars in Neurology 2003;23(4).
- Pinsky L, DiGeorge
AM. Congenital familial sensory neuropathy with anhidrosis. J Pediatr
- National Institute
of Neurological Disorders and Stroke: NINDS Lesch-Nyhan Syndrome Information
Page. Available at:
http://www.ninds.nih.gov/disorders/lesch_nyhan/lesch_nyhan.htm. Accessed February 13, 2007
- Medscapeís Continually
Updated Clinical Reference: Lesch-Nyhan Syndrome. Available at:
http://emedicine.medscape.com/article/1181356-overview. Accessed Jun 29th, 2010.
- Edwards-Lee TA.
Cornford ME, Yu K-T T. Congenital insensitivity to pain and anhidrosis
with mitochondrial and axonal abnormalities. Pediatr Neurol 1997;17:356-361.
Update's blog: Congenital
Insensitivity to Pain with Anhidrosis. Available at:
http://serendip.brynmawr.edu/exchange/node/1736. Accessed April 1st, 2008.