Cancer and Skin Lesions (7)
Sympathectomy and Hyperhidrosis Treatments (7)
Dermatological diseases and infestations (5)
Genetic and rare skin diseases. (5)
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Erythermalgia, a rare painful disorder, is characterized by recurrent pain attacking, warmth, and erythema that mainly involves the distal extremities. Red ear syndrome shares similar clinical features of erythermalgia afflicting the external ear with unilateral/bilateral distribution. The treatments of both diseases are still difficult without controlled therapeutics available up to date. A 12-year-old boy was referred because of 3 years of recurrent attacking of painful erythema and warmth that involved the ears alone, the episodes occurred several times daily with duration of dozens of minutes to hours for each flare. The symptoms could be relieved by cold water and triggered by heat stimuli as well as exciting and movement, and showed mild response to gabapentin, celecoxib, and topical lidocaine compounds in combination, but moderate to blocking injection of botulinum toxin to nervus auricularis magnus. However, systemic itraconazole 200 mg daily resulted in an excellent response after 5-week treatment, leading to milder erythema, warmth and burning sensation, shorter duration, and fewer relapses. The treatment continued for 6 months and then itraconazole was decreased to 100 mg daily for another 6 months until it was stopped, with maintenance of good conditions. In 3 months of follow-up after the treatment ceased, the patient had only 7 to 8 attacks over 10 days presenting as tolerable erythema that lasted for less than 10 min and relieved spontaneously, with absence of warmth and no need of treatment. We considered the patient to be a variant of erythermalgia rather than a red ear syndrome. The results showed that erythermalgia might involve the ears alone and itraconazole might be a potential agent for its treatment.
Naik H, Zhao Y, Forrestal F, Cleall S, Bockbrader H , et al.
European journal of drug metabolism and pharmacokinetics •
Vixotrigine is a voltage and use dependent sodium channel blocker currently under development for treatment of various neuropathic pain indications. The objective of this work was to develop a population pharmacokinetic model and assess effects of various covariates on pharmacokinetic parameters of vixotrigine. Plasma concentration-time data from 12 Phase 1 or 2 studies were included in the analyses. The data were obtained following administration of single or multiple doses of vixotrigine in healthy volunteers and patients. One- and two-compartment pharmacokinetic models were evaluated as base structural pharmacokinetic models. The inclusion of selected covariates was assessed using a stepwise backward elimination approach (α = 0.001) once the base/full model was developed. The predictive ability of the model was evaluated using a visual predictive check (VPC). The final model was used to evaluate effect of covariates on exposure of vixotrigine. A total of 10,263 pharmacokinetic samples collected from 465 subjects were included in the analyses. The pharmacokinetics of vixotrigine was adequately described by a two-compartment model with two transit absorption compartments and first-order elimination. Predictability of the model was also established by VPC. The final model included covariates of age, weight and carbamazepine co-administration on clearance, weight on central volume of distribution, food on absorption rate constant and formulation and Japanese race on bioavailability. None of the covariates identified had a clinically relevant effect, as impact on area under the plasma concentration-time curve (AUC) and maximum plasma concentration (C) was within ± 25%. The model characterizes the pharmacokinetics of vixotrigine well, and the exposure of vixotrigine was comparable between healthy subjects and patients. None of the covariates evaluated have a clinically relevant impact on the pharmacokinetics of vixotrigine.
Erythermalgia is a rare cutaneous disease characterized by episodic attacks of burning pain, erythema, and increased temperature. It primarily involves the extremities, with possible extensions to the ears, face, neck, and scrotum; in rare instances, it may afflict the ears, face, or the scrotum alone. Although various medications alone or in different combinations have been tried with significant variations in response, no recommended therapeutics have been established until very recently. This report presents two case histories of a 20-year-old and a 46-year-old woman, respectively, who displayed intermittent facial erythema associated with warmth and pain during the episodes and who presented normal between episodes. Both had good response to combinative treatments of systemic medication and topical lidocaine compounds. The younger was disease-free after more than 4 years of follow-up, and the older had recurrence after stopping the treatment. Conclusion: Erythermalgia may involve the face alone, and combinative approaches may be of choice for its treatment. Topical lidocaine compounds are considered to be a good option for palliative treatment.
Erythromelalgia is a rare clinical syndrome characterized by episodic attacks of burning pain, erythema, and increased temperature, primarily affecting the extremities, and in rare instances, involving the ear, face, neck, and the scrotum. The dermatoscopic features of erythromelalgia in a case with solely facial involvement have never been described previously. We describe a 14-year-old female who presented with erythema, burning sensation, and warmth on her face only, which mimic the features of erythromelalgia. Physical examination showed higher temperature on the involved cheeks than on axillas during the episode, while the temperature on both areas was the same between episodes. Dermatoscope showed more dilated vessels inside the erythema during the episodes than between the episodes. The symptoms had excellent response to the combination treatment of gabapentin, indomethacin, and topical lidocaine compounds. The present case is considered to be a variant of erythromelalgia. Its erythema may be resulted from the dilated vessels. Combination of modalities may provide effective management for erythromelalgia. "Erythermalgia" may be better than "erythromelalgia" to describe such conditions.