[2013 update about arthropod envenomations in French Guyana]

French Guiana, by its geographical situation, its climate and its biodiversity, is often called "the green hell". Indeed, this French department of America shelters a wildlife rich, abundant among which many species of arthropods, some of which are responsible for envenomations. These accidents consist of scorpion's or hymenoptera's stings or spider's bites. The associated clinical aspect is variable, from simple pain to circulatory collapse, or lung oedema. However, symptomatology is generally mild; four deaths associated to arthropod envenomations have been reported in the past 25 years. This article focuses on envenomations in French Guiana, describing favoring human behavior, risks and venoms associated with the main related animal species.

[Feeding venomous insects among the people and the measures to curb and control this addiction by the government in the Song Dynasty]

Feeding venomous insects, a mystic witchcraft of producing poisonous materials to spoil other people has a long history which was still popular in the southern part of the Song Dynasty, aiming at revenge of one's enemy and the occupation of other's property. The Song government took a strict measures to tackle it, including enacting a decree to prohibiting it, encouraging people to report such malpractice, punishing heavily the person committing such criminal behavior and, at the same time, providing recipes and medicines to remedy its ensued disorders. All of these were helpful to the improvement of social morality.

Anaphylaxis - identification, management and prevention

OBJECTIVE

This article summarises current knowledge regarding the identification, management and prevention of anaphylaxis, highlighting risk minimisation strategies relevant to general practitioners.

DISCUSSION

The most common causes of anaphylaxis are medication, food and insect venom. Medications are the most common cause of anaphylaxis in older adults, particularly antibiotics, anaesthetic drugs, nonsteroidal anti-inflammatory drugs and opiates. Food allergy is the most common cause of anaphylaxis in children, but rarely results in death. Anaphylaxis is a medical emergency requiring immediate treatment with adrenaline, as well as ongoing management. Important steps for long-term risk minimisation include avoidance of triggers, prescription of an adrenaline autoinjector, maintenance of a personalised emergency action plan for anaphylaxis, education for patients and families and regular review to optimise management.

[Adaptation of Vespide Allergy Quality of Life Questionnaire for Polish children with venom allergy and for their parents]

Aim of the study was to assess validity and reliability of adaptations of VQLQ for Polish children with Hymenoptera venom allergy and their parents. Sample under study consisted of 73 children aged up to 14 years, who were treated with specific venom immunotherapy (VIT) in 2008 in centres conducting this procedure in Poland, and their parents. Theoretical validity of the scales was assessed with exploratory factor analysis using principal component analysis method. Reliability of the scales was assessed in terms of internal consistency with Cronbach alpha coefficient. Results of analysis showed that both scales measure 4 dimension of quality of life and reliability of scales measuring particular dimensions is at least acceptable in case of scale for children, and high in case of scale for parents. Both adapted scales are valid and reliable tools measuring quality of life in children with Hymenoptera venom allergy and their parents' quality of life in the face of child's allergy.

[Health-related quality of life in children with Hymenoptera venom allergy treated with VIT and quality of life of their parents]

Hymenoptera venom allergy, although rare in children, by its potential fatalities, leads to many psychosocial consequences, influencing quality of life of children and their parents. Aim of this paper is the estimation of health-related quality of life of venom allergic children treated with specific immunotherapy, and their parents. Assessment of factors influencing health-related quality of life levels was also performed.

MATERIAL AND METHODS

Sample under study consisted of 73 children: mean age 10.6, SD 2, 4, treated because of Hymenoptera venom allergy in 5 clinical allergy centers in Poland. Data was collected using VQLQ questionnaire adapted for children and their parents. Determinants of quality of life were assessed with multivariate linear and logistic regression models. Analysis were done with SPSS 15 for Windows package.

RESULTS

Girls reported higher level of anxiety than boys (B = 0.47; 95% CI = (0.01; 0.94)). Level of caution in children increased along with increase of their anxiety against re-sting (B = 0.49; 95% CI = (0.27; 0.71)). Level of anxiety of children who were under treatment from 6 months to 2 years was lower than level of anxiety of parents of children treated shorter than 6 months (B = -1.21; 95% CI = (-2.16; -0.25)). The lowest level of caution was reported by parents of children aged 10 year or less (B = -0.86; 95% CI = (-1.67; -0.05)), while the highest was reported by parents of children aged 11 years (B = 0.86; 95% CI = (0.20; 1.53)) in comparison to parents of children aged 12 years or more. Parents' caution increased along with increase of their anxiety (B = 0.61; 95% CI = (0.40; 0.83)). Higher level of limitations was imposed by parents of children treated with rush or ultra rush method, in comparison to parents of children treated with conventional method (B = 1.27; 95% CI = (0.21; 2.33)). Levels of quality of life in children and their parents were strongly dependent in the same dimensions.

CONCLUSIONS

1. Levels of quality of life in particular dimension in children is related to level of the same dimension in parents. 2. Age of children influenced level of caution of their parents. 3. Treatment duration influenced level of anxiety of parents. 4. Safety feeling acquired by parents at the beginning of treatment improves their quality of life in all dimensions.

Centipede bites in Hawai'i: a brief case report and review of the literature

In this article, a local case of a centipede bite, with fairly typical symptoms and an uncomplicated course, is presented. The literature is reviewed, indicating that serious complications, while rare, are possible. The author recommends that clinicians structure assessments of centipede bites around knowledge of serious potential complications and provide counseling on prevention of future attacks.

The venom of the Lonomia caterpillar: an overview

Contact with the Lonomia caterpillar causes numerous accidents, especially in Venezuela and the southern region of Brazil, where it is considered a public health problem. The Lonomia obliqua venom causes disseminated intravascular coagulation and a consumptive coagulopathy, which can lead to a hemorrhagic syndrome. The venom of Lonomia achelous also causes hemorrhage, but through increased fibrinolysis. In vivo and in vitro studies have shown that the venom of the Lonomia caterpillar contains several toxins with procoagulant, anticoagulant and antithrombotic activities. These toxins also affect the endothelium. The recent construction of cDNA libraries of the transcripts from L. obliqua bristles enables the use of biotechnological approaches to study the venom. This paper presents an overview of the biochemical and biological properties of Lonomia caterpillar venom, discussing aspects of human accidents, experimental envenomation, toxins and targets and future perspectives.

Hymenoptera Stings

The medically important groups of Hymenoptera are the Apoidea (bees), Vespoidea (wasps, hornets, and yellow jackets), and Formicidae (ants). These insects deliver their venom by stinging their victims. Bees lose their barbed stinger after stinging and die. Wasps, hornets, and yellow jackets can sting multiple times. Most deaths related to Hymenoptera stings are the result of immediate hypersensitivity reactions, causing anaphylaxis. Massive envenomations can cause death in nonallergic individuals. The estimated lethal dose is approximately 20 stings/kg in most mammals. Anaphylactic reactions to Hymenoptera stings are not dose dependent or related to the number of stings. Bee and wasp venoms are made up primarily of protein. Conversely, fire ant venoms are 95% alkaloids. Four possible reactions are seen after insect stings: local reactions, regional reactions, systemic anaphylactic responses, and less commonly, delayed-type hypersensitivity. Clinical signs of bee and wasp stings include erythema, edema, and pain at the sting site. Occasionally, animals develop regional reactions. Onset of life-threatening, anaphylactic signs typically occur within 10 minutes of the sting. Diagnosis of bee and wasp stings stem from a history of potential contact matched with onset of appropriate clinical signs. Treatment of uncomplicated envenomations (stings) consists of conservative therapy (antihistamines, ice or cool compresses, topical lidocaine, or corticosteroid lotions). Prompt recognition and initiation of treatment is critical in successful management of anaphylactic reactions to hymenopteran stings. Imported fire ants both bite and sting, and envenomation only occurs through the sting. Anaphylaxis after imported fire ant stings is treated similarly to anaphylactic reactions after honeybee and vespid stings. The majority of Hymenopteran stings are self-limiting events, which resolve in a few hours without treatment. Because life-threatening anaphylactic reactions can progress rapidly, all animals stung should be closely monitored and observed. In the following review article, we will examine the sources and incidence, toxicokinetics, pathological lesions, clinical signs, diagnosis, treatment, and prognosis for dogs and cats suffering Hymenoptera stings.

Erucism in New Zealand: exposure to gum leaf skeletoniser (Uraba lugens) caterpillars in the differential diagnosis of contact dermatitis in the Auckland region

There are no indigenous caterpillars known to be associated with erucism, but the recently established gum leaf skeletoniser (Uraba lugens) has venom-containing spines that cause adverse reactions in humans. Symptoms are usually characterised by a stinging sensation, followed by itching and the formation of wheals. Exposure to U. lugens should be considered by medical practitioners in the differential diagnosis of contact dermatitis in the Auckland region.

Mastocytosis and Hymenoptera venom allergy

PURPOSE OF REVIEW

Mastocytosis is a rare disease characterized by increased mast cells in skin and/or internal organs. We evaluate the impact of mastocytosis on diagnosis and treatment of Hymenoptera venom allergy.

RECENT FINDINGS

Patients with Hymenoptera venom allergy who suffer from mastocytosis develop life-threatening sting reactions more often than those who do not. When patients with Hymenoptera venom allergy were systematically examined for mastocytosis, it was found to be represented to an abnormally high extent. Most patients with mastocytosis tolerate venom immunotherapy with no or only minor systemic symptoms. Venom immunotherapy was found to be marginally less effective in patients with mastocytosis than in those without evidence of mast cell disease (defined as absent cutaneous mastocytosis combined with a serum tryptase concentration of <11.4 microg/l). Several deaths from sting reactions were reported in patients with mastocytosis after venom immunotherapy was stopped. These patients should have venom immunotherapy for the rest of their lives.

SUMMARY

Patients suffering from mastocytosis and Hymenoptera venom allergy are at risk from a particularly severe sting anaphylaxis. They need optimal diagnosis and treatment. In patients presenting with Hymenoptera venom allergy, screening tests by measurement of serum tryptase concentration, and a careful skin examination, are highly recommended.

[Diagnosis and treatment of insect venom allergy. An important allergic issue for the ear, nose and throat specialist]

The increasing incidence and the potentially life-threatening reactions to venom stings indicate the necessity for otolaryngologists to have a basic knowledge of the diagnosis and treatment of venom allergy. The diagnosis of insect venom allergy is based on the history, skin prick testing (ideally performed as a titration series), and in vitro analysis of specific IgE antibodies to venoms. An emergency medication kit should be prescribed for the patient in case of future venom stings, comprising an H1-blocking antihistamine, a steroid and an adrenaline pen for self-injection. Subcutaneous allergen-specific immunotherapy (sSIT) is the standard treatment to avoid allergic reactions following venom stings in the future. SIT is indicated following all immediate-type reactions to venom stings; contraindications relate to the general recommendations of allergen-specific immunotherapy. Aqueous as well as alum-adsorbed depot allergen preparations can be used for subcutaneous injections. The important dose-increase phase can be performed using conventional, cluster, rush or ultra-rush schedules. Specific immunotherapy is successful in nearly 90% to 100% of patients after 3-5 years of treatment.

Acute myocardial infarction in a young man caused by centipede sting

It is known that insects can cause various clinical effects such as myocardial ischaemia and hypotension from vasospasm and the myocardial toxic effects of the venom and anaphylaxis. Although myocardial ischaemia resulting from centipede sting has been reported once before, myocardial injury has not. In this report, the authors present the case of a 20 year old male patient bitten by a centipede and admitted to the emergency room with chest pain, abnormal electrocardiographic findings, and increased cardiac enzymes (cardiac troponin T) suggesting acute myocardial infarction.

Immunochemical detection of Lonomia obliqua caterpillar venom in rats

Severe cases of human envenoming by caterpillars of the saturniid moth Lonomia obliqua in Brazil can result in renal damage, leading to renal failure, and intracerebral hemorrhaging. In this work, we used immunohistochemical staining with rabbit antiserum raised against L. obliqua venom to examine venom distribution in selected tissues of the brain (cerebellum and hippocampus), kidneys, and liver of male Wistar rats injected with a single dose of venom (200 microg/kg, i.v.) and sacrificed 6, 18, 24, and 72 hours later. The immunolabeling of GFAP was also examined to assess the venom effects on perivascular astrocytic end-feet in the microvasculature of the hippocampus and cerebellum. Venom was detected in the kidneys (6 and 18 hours) and in the liver (6 hours) but not in the brain at any of the time intervals examined. In contrast, immunolabeling for GFAP revealed astrogliosis in the cerebellum and enhanced expression of this protein in the glial processes of the cerebellum and hippocampus, with a maximum response from 24 hours onwards. The high immunoreactivity seen in the kidneys agreed with the renal damage and dysfunction reported for some patients. The lack of venom detection in the brain, despite the altered expression of GFAP in astrocytes, suggested either that the venom does not enter this organ or that its entrance is transient and fast. Alternatively, the circulating venom may induce the release of mediators that could serve as second messengers to provoke the late astrocytic reactivity and astrogliosis. It is possible that both of these mechanisms may contribute to the effects observed.

[Side effects of specific immunotherapy in patients with hymenoptera venom allergy]

The aim of this study was to estimate safety of specific immunotherapy to insects' venom. The frequency of side effects was compared in two groups of patients: subjects with hypersensitivity to insects' venom only and patients with allergy to other allergens. In the examined group of 32 patients with Hymenoptera venoms allergy skin prick tests with common aeroallergens were performed in 30 subjects. In 18 patients (60%) at least one test was positive. In 23 patients (71.9%) immunotherapy with Hymenoptera venom was connected with side effects observed just after administration of vaccine. They were mainly local reactions (itching, redness and oedema). In 6 patients late reactions were observed. No correlation has been found between frequency of side effects of immunotherapy and positive results of skin prick tests. However systemic reactions were revealed only in the group of patients with at least one positive result of skin prick tests.

Prospective study of definite caterpillar exposures

Exposure to caterpillars results in a variety of clinical effects depending on the species involved. The aim of this study was to describe the clinical effects from caterpillar exposures within Australia. Cases were recruited prospectively from calls to a poison information centre. Subjects were included if they had a definite exposure and they had collected the caterpillar or cocoon. The caterpillars were identified to genus and species level where possible. There were 36 included cases: two were contact exposures to caterpillar contents, one was an ingestion of a caterpillar and the remaining 33 patients had definite reactions from caterpillar or cocoon exposure. There were five families of caterpillars identified in the study: Arctiidae, Limacodidae, Anthelidae, Lymantriidae and Sphingidae, many of which occur worldwide. Clinical effects ranged from severe pain to an urticarial response depending on the species involved. There were no adverse effects following ingestion in this study. Treatment consisted primarily of removal of the caterpillar or cocoon. Other treatment measures consisted of symptomatic treatment such as ice packs and antihistamines. This is the first prospective study of caterpillar exposures within Australia and demonstrates that exposures can result in a variety of reactions depending on the family and species involved.

Lonomia obliqua venom action on fibrinolytic system

Accidental skin contact with the Lonomia caterpillar bristles causes a severe hemorrhagic syndrome. While fibrinolytic activation is considered to be the main cause of hemorrhage in Lonomia achelous envenomation, a consumptive coagulopathy was found to be a major component involved in the bleeding complications observed in patients envenomed by contact with Lonomia obliqua. Although we have previously observed that in L. obliqua envenomations, fibrinolysis activation appeared to be secondary to coagulation system activation, there are no reports regarding the ability of L. obliqua venom to activate directly fibrinolytic pathways. We examined the action of L. obliqua crude bristles extract (LOCBE) on several fibrinolytic system components. We demonstrated that LOCBE degraded the A-alpha fibrinogen chain only at high concentrations and after long incubation times. Under these conditions, LOCBE also induced prolongation of the fibrinogen clotting time, but no clot lysis was observed before 24 h. LOCBE did not contain t-PA- or u-PA-like activities. Gel filtration and SDS-PAGE showed that LOCBE did not induce FXIII digestion. In addition, no FXIII activity inhibition was detected by dansylcadaverin method. FXIII levels remained unchanged when FXIII was measured in fibrinogen-depleted LOCBE-treated rat plasma, suggesting that the observed 50% FXIII reduction in rats was related to consumption. In conclusion, our results clearly demonstrated that LOCBE did not display either FXIII inhibition or degradation nor fibrinolytic activity. Furthermore, although proteolytic activity on Aalpha fibrinogen chain was observed, cross-linked fibrin was not affected by LOCBE.

[Accidents due to lepidoptera with special reference to Lonomia sp]

Human poisoning by Lepidoptera (butterflies, caterpillars and moths) has been known to physicians since old times. In the last few years, several factors have been causative of a great number of contacts between different stages of these insects and humans, occasionally with epidemic features. Species of medical interest in Argentina are those related to Megalopygidae, Saturniidae, Hemileucidae, Arctiidae, Notodentidae and Eucliedae families. Among all the species involved, it is important to describe the pathology produced by contact with Lonomia obliqua caterpillar (Saturniidae). The caterpillar Lonomia has several enzymes with procoagulant and fibrinolytic activities, acting on various components of the hemostatic system inducing hemorrhage that can lead to death. In the South of Brazil during the last years caterpillars of this butterfly caused a great number of cases of erucism including some deaths. In the past two years, there have been some cases of poisoning by Lonomia obliqua in Misiones, in the North East of Argentina on the border with Southern Brazil. This presents a potential risk, taking into account the poor knowledge regarding this insect and its venom in Argentina. This brief actualization gives some biochemical, clinical and epidemiologic tools towards understanding human Lepidopterism, an uncommon medical problem in this country.

Centipede (Scolopendra gigantea Linneaus 1758) envenomation in a newborn

The first case of centipede (Scolopendra gigantea Linneaus 1758) envenomation in a newborn is reported. When first examined, approximately 6 hours after the bite, the 28-day-old girl was irritable, with uncontrollable cry and intense local pain, oedema, local hyperthermia, and blood clots at punctures. Uncontrollable crying in neonates should rise the possibility of an insect or arachnid sting.

Arthropod poisons and the cardiovascular system

Animal poisons induce myocardial damage after envenomation. The cardiac manifestations after black widow spider bite are rarely observed and their prognostic significance are not known. Hymenoptera induce anaphylactic manifestations commonly observed in adults with previous coronary artery disease although myocardial involvement is observed in a few without previous heart disease. The mechanism of cardiac involvement after scorpion envenomation has been elucidated, however after widow spider bite or hymenoptera stings the mechanism of myocardial damage of those without previous heart disease is not clear.

Hypertension and abdominal pain: uncommon presentation after exposure to a pine caterpillar

The pine caterpillar Thaumatopoea wilkinsoni is found in pine woods all over Israel. Contact with its hair usually results in local reactions. Systemic reactions after contact with caterpillar hairs are known in other caterpillar species, but have been described only once after contact with T. wilkinsoni. We describe a group of adolescents who were exposed to T. wilkinsoni while camping in a pine wood. Three of them were referred to an emergency department. They had severe pruritus, pain and edema at the contact sites, with papular and urticarial rashes. Two of the patients had abdominal pain and one patient had hypertension for several hours. The hypertension resolved spontaneously.

CONCLUSION

Skin eruptions are the most common manifestations of T. wilkinsoni contact, however, although systemic manifestations are rare, abdominal pain and hypertension may occur.

Stinging insect allergies. Assessing and managing

BACKGROUND

Mortality secondary to insect sting anaphylaxis, though uncommon in this country, is a genuine risk to patients with venom hypersensitivity. A number of non specific and specific preventive measures are available to minimise this risk. They include proper patient counselling regarding sting avoidance and the use of self injectable adrenaline, as well as venom specific immunotherapy.

OBJECTIVE

This article attempts to review the spectrum of insect sting reactions, their appropriate assessment and subsequent management. Anaphylaxis is particularly emphasised with regard to first aid treatment and subsequent prevention.

DISCUSSION

The most common causes of insect stings in Australia are bees and wasps. Insect sting reactions cover a spectrum of responses, from normal to anaphylactic. Immunotherapy is indicated in those patients who experience anaphylactic responses. The presence of venom specific IgE must be demonstrated before commencing immunotherapy. Venom sensitive patients should be educated in anaphylaxis first aid with adrenaline self injectable syringes.

Centipede ingestion by a six-month-old infant: toxic side effects

Centipedes are a common household arthropod whose bite usually causes only local reactions. Ingestion of centipedes has not been previously reported. This article reports the case of a six-month-old infant who ingested a centipede of the Scutigera morpha species and had systemic side effects probably due to systemic absorption of its venom. The child recovered spontaneously after 48 hours. This case illustrates that toxic effects may be noted after ingestion of arthropods and that in this type of centipede no active intervention may be necessary.

Envenomation by the puss caterpillar (Megalopyge opercularis)

We discuss the case of a 52-year-old woman who developed urticarial lesions after the acute envenomation of a puss caterpillar (Megalopyge opercularis). The puss caterpillar, one of more than 50 species of caterpillars that can cause envenomation in the United States, is considered to be one of the most serious. Its clinical presentation and current recommended treatments are reviewed.

Severe systemic reactions to Hymenoptera stings in three dogs

Three dogs were treated for acute severe systemic reactions following Hymenoptera stings. The reactions were characterized clinically by CNS depression, shock, and hemorrhage, and clinicopathologically by inflammation, liver injury, renal disease, hypoproteinemia, and possible disseminated intravascular coagulation. The severe systemic reaction may have resulted from allergic mechanisms, toxic, nonimmunologic mechanisms, or both. Rapid correction of hypovolemia and prevention of vascular stasis are the most important aspects of treatment.

Funnel-web spider (Atrax robustus) antivenom in the treatment of human envenomation

Envenomation by the Sydney funnel-web spider may lead to serious illness or death. After an antivenom which had been raised in rabbits was proven to reverse the signs of envenomation in animals, a trial was conducted in patients. Nine patients (aged 3-82 years) with severe envenomation by funnel-web spiders received treatment with an antivenom to the venom of Atrax robustus. Concomitant diseases in the victims included rheumatoid arthritis, diabetes mellitus, complete heart block, pyrexia of unknown origin, and carcinoma of the ovary, which were being treated with appropriate drugs. Because of the introduction of the antivenom, the syndrome which previously caused either death or a hazardous illness which required two to three weeks of hospital care now became an illness lasting one to three days. So far there have been no definite adverse reactions to the antivenom. There have been no deaths since the antivenom has been used, and it is hoped that human fatalities as a result of funnel-web spider envenomation will become a thing of the past.

Spider (Latrodectus hesperus) poisoning through the conjunctiva. A case report

Spider poisoning is usually a result of the direct bite, envenomation through the chelicera, of the spider. Reported is an unusual case in which poisoning occurred through the conjunctiva when a fragment from a smashed black widow spider (Latrodectus hesperus) flew into a patient's eye. In addition to an immediate local reaction involving the periorbital tissues, the patient experienced systemic effects.

Arthropod envenomations

Millions of arthropods surround us every day, but only a few are medically harmful. Knowledge of the habits and habitats of known venomous arthropods is certainly advisable for the prudent person in areas of known infestation as a preventive measure. Arthropod envenomations probably produce much less mortality than previously thought, but the potential for severe effects of direct envenomation or allergic response exists with some species, and these events must be approached as true medical emergencies.

Fire ant envenomation in children

Fire ants (Solenopsis richteri and Solenopsis invicta) have received scant attention from individuals other than agriculturists, entomologists, and victims of the bite and sting. Since their original importation into Mobile, Alabama, these small, seemingly benign, creatures have slowly migrated throughout most of the southern United States. Not unexpectedly, physicians working in the southern portions of the United States have been confronted with increasingly large numbers of patients, particularly children, who have been bitten and envenomated by these insects. Information regarding the pathogenesis of fire ant bite reactions and an approach to treatment are provided.

Red-back spider (Latrodectus mactans hasselti) envenomation in a neonate

A case of red-back spider (Latrodectus mactans hasselti) envenomation in a neonate is presented. The signs of envenomation in a neonate are discussed, together with the dose of antivenom necessary for the successful treatment of envenomation. In episodes of untractable crying in neonates, the possibility that the baby has been bitten by a red-back spider should be considered.

Black widow spider bites

Black widow spiders (Latrodectus species) are found worldwide. Envenomation of humans usually occurs as the result of chance intrusion into the spider's domain by the human. The venom is regarded as one of the most potent biologic toxins. The venom acts by destabilization of cell membranes and degranulation of nerve terminals resulting in the release of neurotransmitters. The clinical picture is characterized by painful muscle spasm and hypertension. The very young, the elderly or enfeebled, and those with cardiovascular disease are at greatest risk. While not always necessary, the most effective treatment is specific antiserum. Muscle relaxants, analgesics and intravenous calcium are useful adjuvant treatment.

Loxoscelism and necrotic arachnidism

The Brown recluse spider has emerged into a potent venomous creature. Loxoscelism and necrotic arachnidism is not an infrequent medical problem. Spiders other than L. reclusa are capable of inflicting painful and persisting necrotic wounds, however, management of the local cutaneous lesions are similar. Systemic complications of loxoscelism appear to be characteristic for spiders of the genus loxosceles. The authors review an indepth discussion of the spider, venom, diagnosis, clinical presentation, laboratory findings, treatment, and prevention. The literature on loxoscelism is contradictory because of the individuality of the reaction. Experience with many patients is the only guide to management of these cases.

Disorders of neuromuscular transmission other than myasthenia gravis

Disorders of neuromuscular transmission in humans are caused by a wide variety of agents including systemic diseases, drugs, environmental toxins, animal envenomation, cations, and hormones. Some are genetically determined. Many are of known etiology. All such disorders interfere with one or more events in the sequence whereby a nerve impulse excites a muscle action potential. In many disorders of neuromuscular transmission, abnormal fatigue occurs, and some cases respond dramatically to treatment. Investigation of the microphysiology, microanatomy, and pharmacology of both normal and diseased neuromuscular junctions has increased our knowledge of these disorders.