Botulinum toxin type D blocks autonomic cholinergic synapses in humans: discussion of a potential therapeutic use.

Based on epidemiological data it was believed that botulinumtoxin type D (BT-D) may not block human cholinergic synapses. We wanted to investigate BT-D's effect on the autonomic cholinergic synapse in humans. For this, we compared in four volunteers intraindividually the hypohidrotic effect of intradermal BT-D and BT-A in Minor's iodine starch sweat test. Altogether, we studied BT-D in doses of 4, 8, 16 and 32MU and BT-A in doses of 2, 4, 8 and 16MU at weekly intervals throughout a period of 13 weeks. All BT doses were diluted in 0.2 ml 0.9% NaCl/H2O. Overall 704 data points were collected. Combined over all four subjects and all four doses BT-D's hypohidrotic effect intensity was half of BT-A's. BT-D's effect peaked around 5 weeks, BT-A's around 7 weeks. BT-D's effect duration was around 12 weeks, of BT-A's was around 14 weeks. For both BT types the hypohidrotic effect was dose dependent. BT-D, when injected intradermally, can block autonomic cholinergic synapses in humans. Compared to BT-A, BT-D's effect intensity was half and its effect duration was some 2 weeks shorter. With its weaker and shorter effect BT-D does not seem to promise therapeutic effects superior to BT-A.

Diffusion of two botulinum toxins type A on the forehead: double-blinded, randomized, controlled study.

BACKGROUND: Different diffusion of different botulinum toxin type A (BoNTA) preparations may account for differences in outcomes in cosmetic clinical practice. OBJECTIVES: A double-blind, randomized, self-controlled study was performed to evaluate the diffusion characteristics of onabotulinumtoxinA and a Chinese type A botulinum toxin (CBTX-A). MATERIALS AND METHODS: Healthy volunteers (N = 20) were recruited to receive a 0.05-mL (2 U) injection of BoTNA at four forehead sites (medial forehead (subcutaneous (SC)) and temporal forehead (intradermal (ID))). On day 14, the Minor's iodine starch test was performed and photographs were taken for calculating the area and dimensions of anhydrotic area. RESULTS: When BoNTAs were different, the anhidrosis ID area was significantly greater with CBTX-A than onabotulinumtoxinA, the vertical dimension was significantly longer with CBTX-A ID than onabotulinumtoxinA ID and the horizontal dimension was significantly greater with CBTX-A ID than onabotulinumtoxinA ID. The area of anhidrosis SC was significantly greater with CBTX-A than onabotulinumtoxinA. When injection depths were different, the mean horizontal dimension was significantly greater with onabotulinumtoxinA SC than ID. Comparing the dimension of the same BoNTA and injection method, the vertical dimension was significantly greater than the horizontal dimension. CONCLUSION: OnabotulinumtoxinA diffuses less than CBTX-A. ID injection technique may result in less diffusion than SC.

Hypohidrosis induced by topiramate in an adult patient.

Hypohidrosis is an uncommon and reversible side effect of topiramate treatment, reported mainly in children. This report presents an adult patient with complex partial seizures who was treated with topiramate and developed hypohidrosis coupled with hyperthermia, related to high environmental temperature and physical exercise. Reduced sweat response was confirmed using the Neuropad test. Signs and symptoms ceased after drug discontinuation. During topiramate treatment, it is important to recognise this side effect, although the exact causal mechanism has not yet been clarified.

Harlequin Syndrome Related to Perioperative Intercostal Blockade: A Case Report.

Harlequin syndrome is a rare syndrome characterized by hemifacial flushing and altered facial sweating, with only a few case reports related to intercostal blockades. We present a case of Harlequin syndrome in a 65-year-old woman after intercostal blockade for video-assisted thoracoscopic lobectomy. One hour postoperatively, the patient became nauseated and presented with flushing of the right half of the face with a clear line of demarcation. Within 3 hours, the flushing disappeared. In this case report, we discuss Harlequin syndrome in relation to intercostal blockade and encourage clinicians to consider this syndrome in the differential diagnosis when encountering similar symptoms.

Headache in three new cases of Harlequin syndrome with accompanying pharmacological comparison with migraine.

BACKGROUND: Harlequin syndrome (HS) is a rare autonomic disorder characterised by unilateral diminished sweating and flushing of the face in response to heat or exercise. Some patients with HS complain of headache. METHODS: We present three new cases to characterise their headache phenotype and pharmacology and review the literature of cases where headache was described. RESULTS Two out of the three patients presented with episodes of unilateral headache associated with exercise: in one case the headache had migrainous features and was contralateral to the side where the flushing occurred, whereas the second patient, who had had migraine attacks in the past, had a brief throbbing headache, with no associated symptoms, ipsilateral to the facial flushing. The third woman had migraine but the attacks were not associated with HS. Pharmacological characterisation suggested the HS and migraine were biologically distinct. HS was not triggered by nitroglycerin and was unaffected by sumatriptan, dihydroergotamine and ergotamine. HS and migraine did not occur together. In the literature, we found six patients with both HS and headache, five of whom had migraine. CONCLUSIONS: These data do not show any correlation between the phenotypic expression of migraine and HS suggesting the syndromes are pathogenetically independent.

Hypohidrosis and hyperthermia during topiramate treatment in children.

Topiramate is one of the newer generation antiepileptic drugs with a beneficial clinical effect on various seizure types. In this study, we present the clinical findings of hypohidrosis and hyperthermia with topiramate in pediatric patients. The data were collected retrospectively on 173 patients diagnosed as epilepsy on topiramate treatment, and hypohidrosis-related symptoms induced by topiramate were found in 22 patients. Their mean age was 64.45 +/- 56.63 months. The mean duration of topiramate treatment was 7.09 +/- 2.46 months, and the mean dose was 5.37 +/- 1.75 mg/kg/day. All of the patients complained of hypohidrosis and hyperthermia. Six (27.2%) of them had facial flushing, 4 (18.1%) had heat sensation and only 1 (4.5%) had lethargy. Hypohidrosis-related symptoms resolved after discontinuation of the medication. In conclusion, children treated with topiramate should be cautioned regarding these potential adverse effects and advised to avoid its use during the hot summer season.

Reversible hypohidrosis with topiramate therapy for chronic migraine.

Topiramate is an anticonvulsant medication that is widely used for migraine prophylaxis. Hypohidrosis and hyperthermia are 2 rare adverse effects of topiramate treatment, which have mainly occurred in pediatric epilepsy patients. Herein, we describe the first case of reversible hypohidrosis in an adult patient treated with topiramate for chronic migraine.

Hypohidrosis-related symptoms in pediatric epileptic patients with topiramate.

BACKGROUND: Topiramate is one of the most commonly prescribed newer antiepileptic drugs. However, we have encountered quite a few cases of pediatric epileptic patients on topiramate complaining about the symptoms related to hypohidrosis. The aim of this study was to determine the incidence and define the clinical characteristics of hypohidrosis-related symptoms with topiramate in pediatric patients. METHODS: Data was collected prospectively on 264 patients diagnosed as having epilepsy and treated with topiramate at the Department of Pediatrics, Chonbuk National University Hospital between July 2004 and July 2006. The data were collected by direct interview after at least 3 months had elapsed from the initiation of the medication. RESULTS: The study group was composed of 70 boys and 81 girls, with a mean age of 33.1 +/- 43.2 months. The mean duration of topiramate treatment was 13.4 +/- 15.0 months; 52 patients (34.4%) were treated with topiramate only and 99 patients (65.6%) were on polytherapy including topiramate; 59 out of 151 patients (39.1%) experienced hypohidrosis-related symptoms: such as facial flushing, lethargy, itching sensation, irritability with hyperthermia, heat sensation or heat intolerance. However, there were no patients complaining of hypohidrosis-related symptoms among those who were taking antiepileptic drugs other than topiramate. CONCLUSIONS: Our results suggest that topiramate induces hypohidrosis-related symptoms more often than we expected, especially in pediatric patients. We recommend that pediatric epileptic patients taking topiramate should be warned to avoid hot and humid environments, especially during the hot summer season.

Hypohidrosis as an immune-related adverse event of checkpoint inhibitor therapy.

Background: Immune checkpoint blockade therapies including cytotoxic-T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein-1 (PD-1) inhibitors have become indispensable tools for treating melanoma and other cancers. An increasing number of diverse cutaneous adverse reactions to immunotherapy have been documented in the literature and have been reported to affect up to 40% of patients treated with targeted therapies. Method & results: Herein, we report a case of a patient with metastatic melanoma treated with checkpoint inhibitor therapy who developed vitiligo, gastritis and hepatitis, all identified as adverse immune events and attributable to his immunotherapy regimen. He subsequently developed acquired idiopathic generalized hypohidrosis with biopsy of lesional skin demonstrating a peri-eccrine lymphocytic infiltrate. Conclusion: These findings suggest this acquired generalized hypohidrosis represents a lymphocyte-mediated adverse immune event related to this patient's checkpoint inhibitor therapy.

Drug-induced hyperhidrosis and hypohidrosis: incidence, prevention and management.

The human sweating response is subject to the influence of diverse classes of drugs. Some act centrally at the hypothalamus or at spinal thermoregulatory centres, while others act at sympathetic ganglia or at the eccrine-neuroeffector junction. Pharmacological disturbances of sweating have broad clinical implications. Drugs that induce hyperhidrosis, or sweating in excess of that needed to maintain thermoregulation, can cause patient discomfort and embarrassment, and include cholinesterase inhibitors, selective serotonin reuptake inhibitors, opioids and tricyclic antidepressants. Drugs that induce hypohidrosis, or deficient sweating, can increase the risk of heat exhaustion or heat stroke and include antimuscarinic anticholinergic agents, carbonic anhydrase inhibitors and tricyclic antidepressants. As acetylcholine is the principal neuroeccrine mediator, anhidrosis is one of the clinical hallmarks by which acute anticholinergic toxicity may be recognized. The symptom of dry mouth often accompanies the less apparent symptom of hypohidrosis because the muscarinic M(3) acetylcholine receptor type predominates at both sweat and salivary glands. Management options include dose reduction, drug substitution or discontinuation. When compelling medical indications require continuation of a drug causing hyperhidrosis, the addition of a pharmacological agent to suppress sweating can help to reduce symptoms. When hypohidrotic drugs must be continued, deficient sweating can be managed by avoiding situations of heat stress and cooling the skin with externally applied water. The availability of clinical tests for the assessment of sudomotor dysfunction in neurological disease has enhanced recognition of the complex effects of drugs on sweating. Advances in the understanding of drug-induced anhidrosis have also enlarged the therapeutic repertoire of effective treatments for hyperhidrosis.

Topiramate associated hypohidrosis and hyperthermia.

Topiramate is a new antiepileptic drug, used for treatment of partial onset seizure and refractory seizures. Although it is well tolerated in children, some adverse effects including hypohidrosis and hyperthermia are reported. We present two children with epilepsy who were treated with topiramate and developed hypohidrosis and hyperthermia.

Hypohidrosis during topiramate treatment: a rare and reversible side effect.

Topiramate is an antiepileptic drug with a beneficial clinical effect on various seizure types. Topiramate does not seem to be associated with serious adverse effects and is also well tolerated in pediatric patients. Only few cases of hypohidrosis have been described. This report presents one young patient with complex partial seizures who was medicated with topiramate when she developed fatigue, headache, intermittent hyperthermia, inability to produce sweat secretion, and dryness of the skin. Reduced sweat response was determined using the Wescor Macroduct collection procedure. Topiramate was discontinued, and within 3 weeks a repeat sweat test was completely normal. At that time, clinical signs had also disappeared. Hypohidrosis is an uncommon and reversible side effect reported in association with topiramate therapy. It is rare in patients on monotherapy. Although a definite causal relationship still needs to be established, this side effect might be attributed to an autonomic dysfunction by inhibition of isoenzymes of carbonic anhydrase localized in human eccrine sweat glands.

Unilateral anhidrosis: A rare complication of thoracic epidural analgesia.

Management of pain following thoracotomy is an important issue for the control of early morbidity. We herein present the case of a patient who was referred to our hospital after a fall from a height. Right-sided multiple rib fractures, hemopneumothorax, and diaphragmatic rupture were detected. Thoracic epidural catheterization was performed for pain management just before thoracotomy. The patient developed unilateral anhidrosis postoperatively. We discuss this rare complication of thoracic epidural analgesia with a review of relevant literature.

Botulinum toxin A (Botox) and sweating-dose efficacy and comparison to other BoNT preparations.

BACKGROUND: Botulinum toxin type A (BoNT/A) is 20-50 times more effective than Botulinum toxin type B (BoNT/B) concerning the treatment of muscular hypercontractions [Sloop, R.R., Cole, B.A., Escutin, R.O., 1997. Human response to botulinum toxin injection: type B compared with type A. Neurology 49, 189-194]. Botulinum toxins block motor nerves as well as autonomic fibres [Rand, M.J., Whaler, B.C., 1965. Impairment of sympathetic transmission by botulinum toxin. Nature 206, 588-591]. OBJECTIVE: Purpose of this study was to analyse the dose dependent reduction of sweating using the BoNT/A preparation Botox and to compare the results with our earlier results analysing Dysport [Braune, C., Erbguth, F., Birklein, F., 2001. Dose thresholds and duration of the local anhidrotic effect of botulinum toxin injections: measured by sudometry. Br. J. Dermatol. 144, 111-117] and Neurobloc (BoNT/B) [Birklein, F., Eisenbarth, G., Erbguth, F., Winterholler, M., 2003. Botulinum toxin type B blocks sudomotor function effectively: a 6 month follow up. J. Invest. Dermatol. 121, 1312-1316]. METHODS: Different doses of Botox were injected subcutaneously (n=27 healthy subjects). Planimetrical analyses of the area of anhidrosis and quantitative sudomotor-axon-reflex testing (QSART) were done after 3 weeks, 3 and 6 months. RESULTS: A threshold dose of 1.25 MU Botox led to anhidrotic skin spots after 3 weeks. The duration of anhidrosis was prolonged for 3 months when 17.5 MU and for 6 months when 50 MU were injected. Anhidrotic area size decreased with time (p=0.001), indicating partial recovery at the edges. After 3 weeks, QSART had significantly decreased to 29% of baseline. With doses of 70 MU or more it decreased to zero. After 3 months, QSART had returned to 68% of baseline and after 6 months to 87%. CONCLUSIONS: Botox dose-dependently suppressed sweating. Comparison to Dysport and Neurobloc revealed a strikingly similar efficacy after 3 weeks and 3 months for all preparations. BoNT/A in general induced a more sustained anhidrosis than BoNT/B.

Symptomatic and asymptomatic hypohidrosis in children under topiramate treatment.

Topiramate (TPM) has peculiar side effects such as speech difficulties, weight loss, oligohidrosis and hyperthermia. We present the frequency and severity of hypohidrosis in our patients under TPM treatment. One hundred and two patients treated with TPM were evaluated retrospectively. Five (8 months-15 years of age) of them experienced symptomatic hypohidrosis manifested with prolonged or intermittent fever. Pilocarpine iontophoresis sweat test had been performed on the five patients before they were managed, and no sweat had been collected in 4/5 cases. Of the 102 patients, 42 who started TPM treatment when the study was established were evaluated prospectively regarding oligohidrosis. First, they were questioned about whether hypohidrosis occurred after TPM. Of 42, 11 patients complained of hypohidrosis. A sweat test was then performed on these 11 patients. Sweat could not be obtained in 5/11, and increased chloride concentration was found in 4/11. However, sweat could be obtained in the patients who had no complaint of hypohidrosis. Pediatricians should be aware of this side effect of TPM to prevent nonrelevant and cumbersome investigations in patients with prolonged or intermittent fever onset during TPM treatment. Our findings suggest that 5% of patients would experience hyperthermia during TPM treatment. Hypohidrosis without hyperthermia would be more frequent. If it is possible to collect sweat in patients who get fever during TPM treatment, it would be highly probable that the fever is not due to hypohidrosis. Increased chloride concentration alone does not seem to be significant for the hyperthermia risk.