The International Association for the Study of Pain defines hyperesthesia as “increased sensitivity to stimulation, excluding the special senses,” which “may refer to various modes of cutaneous sensibility including touch and thermal sensation without pain, as well as to pain.” While hyperesthesia can be used to describe any increased sensitivity to a stimulus, it is commonly used to describe a painful sensation from a stimulus.
Hyperesthesia is a common symptom of neuropathic pain. Neuropathic pain is defined by the International Association for the Study of Pain as “pain caused by a lesion or disease of the somatosensory system.” The neuropathic pain phenotype contains a spectrum of symptoms that can be roughly categorized into positive and negative symptoms. Hyperesthesia is a positive symptom of neuropathic pain. Positive symptoms are categorized as stimulus-dependent pain, stimulus-independent pain, and paresthesias. Neuropathic pain affects about 7-8% of the general population.
In this article, hyperesthesia will be defined as an increased cutaneous sensitivity manifesting as stimulus-dependent neuropathic pain. The most common hyperesthesias are allodynia and hyperalgesia. Allodynia is a pain caused by a stimulus that usually does not elicit a painful response (i.e., pain on light touch). Hyperalgesia is an exaggerated pain response to a stimulus that usually causes pain (i.e., out of proportion pain from a pinprick). While most neuropathic pain symptoms are contained within the dermatomal distribution of the affected nerve, hyperesthesia has been known to extend beyond the affected nerve’s distribution. This can sometimes obscure the correct diagnosis and lead to the inappropriate diagnosis of a psychosomatic disorder.
A detailed history and a thorough physical examination should be sufficient to identify the underlying etiology. Routine laboratories should be ordered as part of the workup. Special laboratory, diagnostic, and imaging tests may have to be ordered to make a definitive diagnosis of the etiology. Treatable and reversible etiologies should be promptly treated. The mainstay of treatment is symptomatic relief via pharmacological, non-pharmacological, and interventional therapies. Symptoms are typically challenging to eliminate, and patients will most likely continue to experience persistent symptoms. A multidisciplinary team approach has been shown to provide the most effective and lasting results.