Notalgia Paresthetica; A Chronic Cutaneus Sensory Neuropathy

Notalgia Paresthetica

1. Notalgia Paresthetica Ade Wijaya, MD – October 2024

2. Introduction First described in 1934 Chronic cutaneous neuropathy primarily characterized by localized pruritus and associated dysesthesias, including sensations of pain, numbness, and tingling Senel , E.; Holt, S.; Sabancılar , E.; Sabancılar , Z.; Do gruer ¸ Senel , S. The etiology of notalgia paresthetica: A descriptive study of 117 patients. Ir. J. Med. Sci. 2020, 189, 1311–1316. Mülko ˘ glu , C.; Nacır , B. Notalgia paresthetica: Clinical features, radiological evaluation, and a novel therapeutic option. BMC Neurol. 2020, 20, 191.

3. Epidemiology / RiSK FACTORS Middle-aged patients (40s-60s) Women : Men = 2-3 : 1 In younger patients associated with multiple endocrine neoplasia type 2B; autosomal dominant pattern Elevated body mass index relaterd to longer disease periode Temperature change has been identified as a potential exacerbating factor Robinson, C., Downs, E., De la Caridad Gomez, Y., Nduaguba , C., Woolley, P., Varrassi , G., ... & Yazdi , C. A. (2023). Notalgia paresthetica review: update on presentation, pathophysiology, and treatment.  Clinics and Practice ,  13 (1), 315-325.

4. Pathophysiology Sensory neuropathy Damage to the posterior cutaneous branches of T2–T6 spinal nerves leads to a thoracic polyradiculopathy. Damage to these spinal nerves is thought to occur from impingement caused by degenerative changes in the spine or by musculoskeletal compression Musculoskeletal nerve compression Robinson, C., Downs, E., De la Caridad Gomez, Y., Nduaguba , C., Woolley, P., Varrassi , G., ... & Yazdi , C. A. (2023). Notalgia paresthetica review: update on presentation, pathophysiology, and treatment.  Clinics and Practice ,  13 (1), 315-325.

5. Presentation Sensory changes and chronic pruritus leading to lichenification and dark pigmentation Patients typically present with symptoms of pruritus or paresthesia located medial or inferior to the scapula, typically in the T2–T6 dermatomes Other sensory changes include pain, change in temperature, paresthesia, hypoesthesia, or hyperesthesia Usually unilateral NP is most commonly found on the left side of the body, opposite the dominant hand Robinson, C., Downs, E., De la Caridad Gomez, Y., Nduaguba , C., Woolley, P., Varrassi , G., ... & Yazdi , C. A. (2023). Notalgia paresthetica review: update on presentation, pathophysiology, and treatment.  Clinics and Practice ,  13 (1), 315-325.

6. Diagnosis History and physical examination Though not needed, a biopsy can be helpful when ruling out other diagnoses. Biopsy of the pigmented lesions may demonstrate hyperkeratosis, macrophages with intracellular melanin accumulation, and necrotic epidermal keratinocytes Maciel AA, W.; Cunha, P.R.; Laraia , I.O.; Trevisan , F. Efficacy of gabapentin in the improvement of pruritus and quality of life of patients with notalgia paresthetica. An. Bras. Dermatol. 2014, 89, 570–575. Weber, P.J.; Poulos, E.G. Notalgia paresthetica: Case reports and histologic appraisal. J. Am. Acad. Dermatol. 1988, 18, 25–30.

7. Differential DIAGNOSIS Pigmented contact dermatitis Patchy parapsoriasis Lichen simplex chronicus Macular amyloidosis Tinea versicolor Robinson, C., Downs, E., De la Caridad Gomez, Y., Nduaguba , C., Woolley, P., Varrassi , G., ... & Yazdi , C. A. (2023). Notalgia paresthetica review: update on presentation, pathophysiology, and treatment.  Clinics and Practice ,  13 (1), 315-325.

8. Treatment Intravenous lidocaine Three infusions of lidocaine were given at two-week intervals to one patient with a dosage of 1 mg/kg bolus followed by a 4 mg/kg infusion administered over one hour Maintenance infusions every 3–4 weeks would be required to maintain symptom alleviation One of the first treatments developed for NP was low- and high-dose topical capsaicin patches Intradermal lidocaine injections 300 mg daily gabapentin Other pharmacological options include corticosteroids, oxcarbazepine, tacrolimus, amitriptyline, a combination of topical amitriptyline/ketamine cream, and intradermal botulinum toxin A Nonpharmacological treatment: Narrow-band ultraviolet B (UVB), physical therapy, Transcutaneous electrical nerve stimulation (TENS) Robinson, C., Downs, E., De la Caridad Gomez, Y., Nduaguba , C., Woolley, P., Varrassi , G., ... & Yazdi , C. A. (2023). Notalgia paresthetica review: update on presentation, pathophysiology, and treatment.  Clinics and Practice ,  13 (1), 315-325.

9. Prognosis and Complications Impact QOL Chronic scratching, which results in skin excoriations, increasing the risk of infections and the development of hyperpigmentation and lichenification Howard, M.; Sahhar , L.; Andrews, F.; Bergman, R.; Gin, D. Notalgia paresthetica: A review for dermatologists. Int. J. Dermatol. 2018, 57, 388–392.

10. Summary Sensory neuropathy Chronic pruritus and paresthesias in a circumscribed region of the mid-to-upper back Postinflammatory hyperpigmentation appearing as a hyperpigmented patch, most commonly along the T2–T6 dermatomes Interdisciplinary / multimodal approaches

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