Wadle M, Szafarowicz B, Nykiel-Bailey S, Tan B, AuBuchon J , et al.
Pain •
Mutations in the SCN9A gene, which encodes the sodium voltage-gated channel alpha subunit 9 on chromosome 2 (Nav1.7), are extremely rare and play a crucial role in pain signaling. Depending on the type of mutation, the clinical presentation of these mutations can vary widely from hyperactive pain phenotypes such as primary erythromelalgia to hypoactive pain phenotypes manifesting as congenital insensitivity to pain. Despite multiple descriptions in the literature of pain-associated behaviors in sodium voltage-gated channelopathies, there are no perioperative guidelines in this patient population that can be used to manage pain-associated procedures. Incorporating reported insights from pain literature into an anesthetic plan may improve perioperative patient satisfaction and outcomes. We present a case of a patient with a novel SCN9A mutation (c.3019C>T) who underwent a common surgical procedure and suffered atypical complications. We propose that her SCN9A mutation may have contributed to these sequelae and recommend a greater familiarity with sodium channelopathies-especially those attributed to the SCN9A gene-to improve perioperative management.
It is essential to be aware of both neoplastic and paraneoplastic vasculitides, vasculopathy, and hypercoagulability, considering the importance of an accurate diagnosis and timely treatment of the underlying malignancy. Characteristics such as the type of vasculitis, age, gender, atypical presentation, and lack of response to common therapies should prompt investigation for an occult malignancy, whereas vasculitis such as GPA require due malignancy vigilance given a significantly increased risk of malignancy at the time of diagnosis and in the following years. Vasculopathies are rarer than vasculitides, but are associated with specific malignancies and, in the context of such malignancies, should be kept in mind. Hypercoagulability is a well-documented neoplastic phenomenon with an increased risk of thrombosis in the setting of positive aPLs. Most neoplastic and paraneoplastic vascular syndromes require no specific treatment outside of treatment of the underlying malignancy. The two key exceptions are PACNS, because of its poor prognosis, and erythromelalgia, in which aspirin is an effective agent.
Erythromelalgia is characterized by episodes of erythematous, warm, burning acral skin, which is exacerbated by heat and relieved by cold. Erythromelalgia usually affects the feet and/or hands but, although rare, erythromelalgia may affect the ears. The authors present a 65-year-old woman with erythromelalgia of the ears with disabling symptoms whose diagnosis was delayed for 6 years. The patient failed to respond to numerous therapies before rapidly improving with oral amitriptyline and amitriptyline 1% to 2% and ketamine 0.5% to 1% topical gel.
