Stevens-Johnson syndrome following occupational exposure to carbamate insecticide

Stevens-Johnson syndrome and toxic epidermal necrolysis: A systematic review of PubMed/MEDLINE case reports from 1980 to 2020

Background

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, life-threatening immunologic reactions. Prior studies using electronic health records, registries or reporting databases are often limited in sample size or lack clinical details. We reviewed diverse detailed case reports published over four decades.

Methods

Stevens-Johnson syndrome and toxic epidermal necrolysis-related case reports were identified from the MEDLINE database between 1980 and 2020. Each report was classified by severity (i.e., SJS, TEN, or SJS-TEN overlap) after being considered a “probable” or “definite” SJS/TEN case. The demographics, preconditions, culprit agents, clinical course, and mortality of the cases were analyzed across the disease severity.

Results

Among 1,059 “probable” or “definite” cases, there were 381 (36.0%) SJS, 602 (56.8%) TEN, and 76 (7.2%) SJS-TEN overlap cases, with a mortality rate of 6.3%, 24.4%, and 21.1%, respectively. Over one-third of cases had immunocompromised conditions preceding onset, including cancer (n = 194,18.3%), autoimmune diseases (n = 97, 9.2%), and human immunodeficiency virus (HIV) (n = 52, 4.9%). During the acute phase of the reaction, 843 (79.5%) cases reported mucous membrane involvement and 210 (19.8%) involved visceral organs. Most cases were drug-induced (n = 957, 90.3%). A total of 379 drug culprits were reported; the most frequently reported drug were antibiotics (n = 285, 26.9%), followed by anticonvulsants (n = 196, 18.5%), analgesics/anesthetics (n = 126, 11.9%), and antineoplastics (n = 120, 11.3%). 127 (12.0%) cases reported non-drug culprits, including infections (n = 68, 6.4%), of which 44 were associated with a mycoplasma pneumoniae infection and radiotherapy (n = 27, 2.5%).

Conclusion

An expansive list of potential causative agents were identified from a large set of literature-reported SJS/TEN cases, which warrant future investigation to understand risk factors and clinical manifestations of SJS/TEN in different populations.

Stevens - Johnson Syndrome and Toxic Epidermal Necrolysis; Extensive Review of Reports of Drug-Induced Etiologies, and Possible Therapeutic Modalities

Stevens - Johnson Syndrome and Toxic Epidermal Necrolysis are adverse hypersensitivity reactions that affect the skin and mucous membranes. They are characterised by erythematous macules and hemorrhagic erosions of the mucous membranes. Epidermal detachments of varying degrees of severity also occur in these conditions. Various aetiologies are associated with these conditions, with adverse drug reaction being the most common. Though the worldwide incidence of these conditions is recorded as low, diverse types of medication are being observed to lead to these conditions. This review compiles information on the details of Stevens-Johnson syndrome and Toxic Epidermal Necrolysis, the pathophysiology, therapeutic management, and largely considers the drug-induced etiologies associated with these conditions.

Organophosphorus and carbamate insecticide poisoning

Both organophosphorus (OP) and carbamate insecticides inhibit acetylcholinesterase (AChE), which results in accumulation of acetylcholine (ACh) at autonomic and some central synapses and at autonomic postganglionic and neuromuscular junctions. As a consequence, ACh binds to, and stimulates, muscarinic and nicotinic receptors, thereby producing characteristic features. With OP insecticides (but not carbamates), "aging" may also occur by partial dealkylation of the serine group at the active site of AChE; recovery of AChE activity requires synthesis of new enzyme in the liver. Relapse after apparent resolution of cholinergic symptoms has been reported with OP insecticides and is termed the intermediate syndrome. This involves the onset of muscle paralysis affecting particularly upper-limb muscles, neck flexors, and cranial nerves some 24-96 hours after OP exposure and is often associated with the development of respiratory failure. OP-induced delayed neuropathy results from phosphorylation and subsequent aging of at least 70% of neuropathy target esterase. Cramping muscle pain in the lower limbs, distal numbness, and paresthesiae are followed by progressive weakness, depression of deep tendon reflexes in the lower limbs and, in severe cases, in the upper limbs. The therapeutic combination of oxime, atropine, and diazepam is well established experimentally in the treatment of OP pesticide poisoning. However, there has been controversy as to whether oximes improve morbidity and mortality in human poisoning. The explanation may be that the solvents in many formulations are primarily responsible for the high morbidity and mortality; oximes would not be expected to reduce toxicity in these circumstances. even if given in appropriate dose.

Compensation for occupational skin diseases

The Korean list of occupational skin diseases was amended in July 2013. The past list was constructed according to the causative agent and the target organ, and the items of that list had not been reviewed for a long period. The revised list was reconstructed to include diseases classified by the International Classification of Diseases (10th version). Therefore, the items of compensable occupational skin diseases in the amended list in Korea comprise contact dermatitis; chemical burns; Stevens-Johnson syndrome; tar-related skin diseases; infectious skin diseases; skin injury-induced cellulitis; and skin conditions resulting from physical factors such as heat, cold, sun exposure, and ionized radiation. This list will be more practical and convenient for physicians and workers because it follows a disease-based approach. The revised list is in accordance with the International Labor Organization list and is refined according to Korean worker's compensation and the actual occurrence of occupational skin diseases. However, this revised list does not perfectly reflect the actual status of skin diseases because of the few cases of occupational skin diseases, incomplete statistics of skin diseases, and insufficient scientific evidence. Thus, the list of occupational diseases should be modified periodically on the basis of recent evidence and statistics.

Clinical Toxicology of Insecticides

Some insects compete for our food, some damage construction materials and some are important disease vectors in humans and animals. Hence, it is not surprising that chemicals (insecticides) have been developed that kill insects and other arthropods. More recently introduced insecticides, such as the neonicotinoids, have been produced with the intent that humans and animals will not be harmed by their appropriate use. This chapter reviews the clinical features and management of exposure to organophosphorus (OP) and carbamate insecticides, neonicotinoids, phosphides and pyrethroids. In the developing world where the ambient temperature is often high and personal protection equipment often not worn, poisoning particularly from OP and carbamate insecticides is common in an occupational setting, though more severe cases are due to deliberate ingestion of these pesticides. Both of these insecticides produce the cholinergic syndrome. The neonicotinoids, a major new class of insecticide, were introduced on the basis that they were highly specific for subtypes of nicotinic receptors that occur only in insect tissues. However, deliberate ingestion of substantial amounts of a neonicotinoid has resulted in features similar to those found in nicotine (and OP and carbamate) poisoning, though the solvent in some formulations may have contributed to their toxicity. Phosphides interact with moisture in air (or with water or acid) to liberate phosphine, which is the active pesticide. Inhalation of phosphine, however, is a much less frequent cause of human poisoning than ingestion of a metal phosphide, though the toxicity by the oral route is also due to phosphine liberated by contact of the phosphide with gut fluids. It is then absorbed through the alimentary mucosa and distributed to tissues where it depresses mitochondrial respiration by inhibiting cytochrome c oxidase and other enzymes. Dermal exposure to pyrethroids may result in paraesthesiae, but systemic toxicity usually only occurs after ingestion, when irritation of the gastrointestinal tract and CNS toxicity, predominantly coma and convulsions, result.