Introduction

Notalgia paresthetica (NP) is a chronic sensory neuropathy¹ or cutaneous neuropathy characterised primarily by localised pruritus-severe itching, burning, tingling, and localised pain to the upper back.¹ Russian physician, Michail Astwazaturow, was the first to describe notalgia paresthetica in 1934.² The "notalgia" name was derived from the Greek words "notos" (back) and "algos" (pain). Often misdiagnosed and overlooked, NP is due to nerve irritation or entrapment, producing pain that significantly impacts activities of daily living. The pathophysiology of NP is unclear.  It is typically assumed to be a neurogenic itch brought on by persistent nerve trauma or spinal nerve impingement. Irritation or damage to the thoracic nerves, specifically thoracic nerves two to six, has been suggested as a causative factor.

Notalgia paresthetica is described as relatively rare, and due to its benign nature and absence of prevalence, few studies have been conducted on this disorder. Despite its benign course, NP greatly affects the quality of life of patients.^{1 2 3 4} Periods of remission and aggravation are common, and the symptoms can last for years.^{2 4 5 6}

Although primarily a neurological condition, a significant psychosomatic component is uncovered by accumulating evidence—sharing and anxiety appear to aggravate NP symptoms, rendering discomfort more intense and exacerbations more prolonged. Stress and anxiety as physiologic and psychologic responses affect a myriad of body systems, including nerve function and skin integrity.⁷ The multifaceted relationship between mental health and NP symptom intensity is explored in this article, with commentary on how psychological distress exacerbates symptoms and what effective interventions can be implemented to control them.⁷

Understanding notalgia paresthetica

Notalgia Paresthetica (NP) is suspected to result from nerve entrapment or irritation,^{2 4 5 8} specifically implicating the dorsal branches of the thoracic spinal nerves (T2 through T6).^{2 5 6 8}  Partial compression or damage to the nerves causes the resultant symptoms.⁸  The condition is most often associated with spinal or musculoskeletal pathology,^{2 5 6} e.g., degenerative spinal change of the vertebrae, imbalance of muscle forces, or postural deformity. The nerve entrapment theory is supported by findings showing an overlap between the dermatomal distribution of NP and the location of spinal pathology observed radiographically. Another study, however, found that this overlap occurred only in 16% of the patients studied, which suggests that spinal abnormalities may not be the explanation for the pathogenesis.

NP is a complex disorder with physical nerve irritation and a faulty itch control system. Trigger or precipitate NP symptoms can be:

• Severe exercise leading to muscular rigidity⁸ or repetitive physical strain.
• Prolonged periods of abnormal posture and inactivity ^{4 8}
• Muscle spasms.^{2 6} 
• Environmental causes such as temperature change or skin irritants ^{1 2}
• Emotional stress and anxiety.⁷
• Additionally, scratching the involved or lesion area can lead to an exacerbation of symptoms of NP.²

Stress and anxiety: an overview

What is stress?

Stress is the physical, emotional, or psychological tension that the body responds to naturally. Stress can be either acute, resulting from temporary challenges that trigger short-term adrenaline rush, or chronic, which lasts over time, keeping the body in a prolonged state of alert and has a negative effect on overall health. Chronic stress was discovered to induce systemic inflammation with impacts on neurological and dermatological diseases. Psychological or emotional stress was found to enhance itch perception.⁷

What is anxiety?

Anxiety refers to chronic worry or fear that could appear in any of several different forms, such as generalised anxiety disorder (GAD), health anxiety, and panic disorders.⁷ The hypothalamic-pituitary-adrenal (HPA) axis is activated during times of stress, which is linked to anxiety.⁷

Anxiety is a psychological and emotional factor that can change how people perceive itch. Medical conditions like Notalogia paresthetica, which lead to chronic itch, are often associated with more frequent episodes of stress, anxiety, and other mood disorders. Stress and anxiety, in turn, exacerbate itch, thereby creating a vicious cycle. Anxious patients typically present with heightened sensitivity to pain and discomfort, which exacerbates existing medical symptoms.

Physiological effects of stress and anxiety on the body

Both anxiety and stress activate the autonomic nervous system(ANS) and cause the secretion of cortisol and other stress hormones.⁷ High cortisol levels can lead to inflammation, immune dysfunction, and alterations in nerve sensitivity, worsening disease symptoms like NP.

Stress is recognised to induce increased corticotropin-releasing factor (CRF) release into the hypothalamus, amygdala, and other areas of the brain.⁷ Over time, this chronic release of CRF may cause long-term synaptic plasticity that contributes to an increased stress response and chronic anxiety, which can result in increased itch and anxiety over time.⁷

Connection between stress, anxiety, and skin/nerve conditions

Stress-induced itch and skin conditions

Psychogenic itch, or stress pruritus, occurs when emotional distress triggers excessive scratching or inflammation without an obvious dermatological cause. Itching due to stress is also common in conditions like eczema, psoriasis, and other neurodermatoses, where psychological factors contribute to the intensity of symptoms.⁷

It has been demonstrated that stress weakens the skin's protective layer, increasing the risk of inflammation and hypersensitivity reactions.  The hypothalamic-pituitary-adrenal (HPA) axis is dysregulated by prolonged stress, resulting in an excess of cortisol. The elevated level of cortisol disrupts immune function, impairing the skin's resistance to environmental stimuli and exacerbating flare-ups

It has been demonstrated that stress exacerbates itching in a vast array of pruritic conditions. They include:

• Psoriasis
• Atopic dermatitis
• Chronic Idiopathic Urticaria
• Acne-related itch⁷

Role of stress in neuropathic pain and sensory disorders

Anxiety plays a significant role in pain perception exacerbation by enhancing central sensitisation—a status wherein the nervous system is very sensitive to stimuli. Individuals with chronic pain disorders undergo stress-induced pain amplification, since psychological distress worsens nerve sensitivity and inflammatory responses. Research further indicates that stress-induced neuroinflammation contributes to the malfunction of nerves that lead to amplified pain perceptions.

How stress and anxiety worsen notalgia paresthetica symptoms

Stress worsens itch and discomfort

Stress is typically a direct precipitant and can predispose susceptible individuals to flares of NP.  The itch-scratch cycle, wherein scratching provides transient relief of itch but ultimately worsens it, applies acutely in NP.  Accentuated stress and anxiety can decrease the threshold of itch perception, rendering the compulsion to scratch more irresistible with ensuing secondary skin trauma. Chronic scratching also results in secondary skin lesions over the involved area, i.e., hyperpigmentation and lichenification, which are observed in patients with chronic NP.^{2 6}

Muscle tension and postural abnormalities

Notalgia Paresthetica is also believed to be a neurogenic itch due to impingement or chronic trauma of the spinal nerves.^{2 8}  Physical etiologies, such as muscle spasms, are speculated to compress cutaneous and itch-sensitive nerves, resulting in aberrant firing and the sensation of itch. A related consideration is that individuals who are anxious also tend to carry physical tension, especially in the neck, shoulders, and back. This constant tension can further aggravate nerve compression and inflammation and contribute to NP symptoms being perpetuated or exacerbated.⁷

Sleep disturbances and fatigue

Patients with Notalgia Paresthetica scratch the involved areas while distracted or asleep, further irritating symptoms.² Stress-induced insomnia is common and lowers pain tolerance. Poor sleep impacts the body's ability to heal and increases cortisol levels, which reinforce inflammation and emotional reactivity.⁷

Psychological feedback loop

The vicious pruritus, stress, and anxiety cycle. This cycle suggests that the anxiety one develops with his or her severe and chronic itch has the capability to feed back into the system and exacerbate the itch.⁷ It has been suggested that if chronic itch represents a chronic stressor, it can sensitise the brain areas involved in anxiety and consequently lead to increased itch and anxiety in the long term.⁷ This process emphasises the theory of a cycle of feedback whereby concern or apprehension about the symptom (itch) causes its intensification. This cycle makes NP increasingly difficult to treat except in cases where the mental condition is treated in combination with physical symptoms.

Symptom → Anxiety → Amplification of symptoms → Increased anxiety

Management strategies

Stress and anxiety reduction techniques

Given the strong correlation of Notalgia Paresthetica (NP) with psychological distress, stress management skills play a significant role in symptom control.

Cognitive-Behavioural Therapy (CBT): CBT is a systematic, evidence-based therapy that helps patients identify and modify negative thought patterns causing stress and anxiety. CBT has been effective in the management of chronic pruritus by helping patients reinterpret anxious thoughts and develop coping skills, thereby reducing the perception of itch and discomfort.⁷

Mindfulness and meditation: Mindfulness meditation has been found to decrease physiological indicators of stress like cortisol levels, and increase the regulation of emotions, which can also decrease inflammation and nerve sensitivity associated with NP. Guided imagery and progressive muscle relaxation meditation practices can enhance stress resilience.⁷

Breathing exercises and progressive muscle relaxation: These lower bodily tension, particularly in neck and back muscles, that compress nerves and reduce the physiological impact of anxiety that can magnify related NP symptoms.^{2 4 7}

Pharmacological interventions

Various drugs are employed to treat Notalgia Paresthetica symptoms, and some of them, or related drugs, exert anti-anxiety activity or are used for the treatment of neuropathic pain, which concomitantly overlaps with NP's neuropathic pathogenesis ^{5 6}

• Oral medication in the form of Gabapentin is a common and successful therapy to reduce itch for notalgia paresthetica. Gabapentin and Pregabalin have also been named as GABA analogues possessing an anti-anxiety action, which have been used for controlling chronic itch, particularly occurring in conjunction with systemic disease or neuropathy. Gabapentin was shown in one clinical study on notalgia paresthetica patients to reduce itch^{1 4 5 6 7}
• Antidepressants such as tricyclic antidepressants have been used to treat chronic itch. Amitriptyline is listed as an oral medication therapy for Notalgia Paresthetica. They and other tricyclic antidepressants are used to treat chronic itch and have potent antihistaminic actions^{4 7}

Lifestyle modifications

Lifestyle and physical therapy come into play, especially in view of the fact that the presumptive cause of Notalgia Paresthetica is normally nerve compression.^{1 2 4  6}

Physical therapy is utilised to help alleviate Notalgia Paresthetica.^{1 2 4} It has proved beneficial for patients and lends evidence to the belief that nerve impingement causes NP.^{1 2 4 5} Individualised physical therapy entails the strengthening of upper paraspinal muscles and the pectoral muscle stretching. This is thought to change the paraspinal muscle tone and relocate the angle at which nerves are irritated, potentially decreasing nerve irritation and pruritus.^{2 4} 

Multidisciplinary approach

Optimal management of Notalgia Paresthetica (NP) is often multidisciplinary and can involve dermatologists, neurologists, and mental health professionals.^{1 2} Dermatologists play a role in diagnosing NP as well as in the management of any secondary skin changes that result from chronic scratching.^{2 5} Neurologists are required for the evaluation of potential spinal or nerve impingement, particularly when structural abnormalities are the reason for the nerve compression.² Stress, anxiety, or psychogenic factors that tend to exacerbate the symptoms of NP may be treated by psychologists or psychiatrists. A combination of the above disciplines establishes a holistic treatment protocol that influences both the neurological and psychosomatic components of NP, resulting in improved patient outcomes and quality of life.^{1 2 5} 

Summary 

Notalgia paresthetica (NP) is a chronic neuropathic dysesthesia that is primarily manifested as intense, localized pruritus, or itching, most often on the medial or inferior back near the shoulder blade.^{1 2 6} Its precise etiology is not entirely known, but thoracic nerve irritation or trauma is suspected.^{1 2 6} Since NP is a chronic itch syndrome, it is directly associated with increased stress, anxiety, and other mood disorders. Critically, anxiety and stress are themselves described as being induced by itch perception, which then is able to worsen this perception in a self-reinforcing cycle whereby distress causes worsening of the itching, producing such behaviour as scratching. This scratching itself produces the characteristic secondary skin changes in NP, such as excoriations and hyperpigmentation.^{1 2 6} This cycle of itch-stress-anxiety negatively impacts patient behaviour and worsens the general prognosis and quality of life, and is described as being recurrent in various chronic itch etiologies. Therefore, although the specific interaction between stress/anxiety and NP symptoms is not described in detail, application of the principles from studies on chronic itch highly suggests that psychological aspects significantly contribute to the worsening of NP's primary symptom, pruritus. This suggests the potential benefit of an integrative management plan that addresses and aims at the psychological impact of the condition and physical interventions.