Eccrine sweat glands are not innervated in hereditary sensory neuropathy type IV

Abstract

The ultrastructural study of a skin biopsy in a patient afflicted with hereditary sensory neuropathy type IV (congenital insensitivity to pain with anhidrosis) did not reveal any unmyelinated axons or axonal terminals around eccrine sweat glands but only processes, partially covered by a basement membrane and therefore resembling Schwann cell processes. The absence of such unmyelinated axons in close proximity to eccrine sweat glands where they normally occur appears to be the morphological equivalent to the anhidrosis and also corresponds to the deficiency of unmyelinated axons in the sural nerve of the same patient, as previously reported.

Nerve Growth Factor-Tyrosine Kinase A Pathway Is Involved in Thermoregulation and Adaptation to Stress: Studies on Patients with Hereditary Sensory and Autonomic Neuropathy Type IV

“…Moderate-to-severe mental retardation is present in most of the patients, and this combination of insensitivity to pain and mental retardation seems to lead to self-mutilation of the tongue and fingertips with frequent autoamputations. Anhidrosis, another prominent component of the disorder, is often associated with recurrent episodes of unexplained fever, which can be fatal (1)(2)(3). Typical histologic findings include a complete absence of nonmyelinated and small myelinated nerve fibers in the dorsal root ganglia and normal number and structure of the sweat glands, but lack of the innervations of small diameters neurons (4).…”

Molecular basis of congenital insensitivity to pain with anhidrosis (CIPA): Mutations and polymorphisms inTRKA (NTRK1) gene encoding the receptor tyrosine kinase for nerve growth factor

“…Levels of mental retardation are variable among CIPA patients. Anhidrosis is explained by a loss of innervation of eccrine sweat glands by sympathetic neurons [Langer et al, 1981]. The absence of reaction to noxious stimuli is attributed to absence of small-diameter afferent neurons responsible for tissue-damaging stimuli in the dorsal ganglia [Swanson et al, 1965;Rafel et al, 1980].…”

“…Anhidrosis (inability to sweat) causes disturbance of the homeostasis responsible for body temperature and recurrent febrile episodes can occur. The anomalous pain and temperature sensation and anhidrosis in CIPA are due to the absence of afferent neurons activated by tissuedamaging stimuli and a loss of sympathetic innervation of eccrine sweat glands, respectively [Rafel et al, 1980;Langer et al, 1981].…”

Anesthesia Procedure for Congenital Insensitivity to Pain in a Child with Anhidrosis Syndrome: A Rare Case

“…Anhidrosis, hyperpyrexia, and febrile convulsions, which may be fatal, occur with impaired autonomic innervation of the eccrine sweat glands 4,5 , and with no sensation of pain and mental retardation, when teeth start to emerge, self-mutilation may lead to injuries of the tongue, lips, oral mucosa, eyes, fingers, and other areas.…”