Exposure-pattern dermatitis due to CS gas

Exposure to the riot control agent CS and potential health effects: a systematic review of the evidence

o-Chlorobenzylidene malononitrile (CS) is one of the most extensively used riot control agents. Our aim was to conduct a systematic review of the potential health effects related to CS exposure. We searched for papers in English between 1991 and 2014. Thirty five (35) studies (25 case reports, seven descriptive studies and three analytical studies) were included in the review. In the twenty five case reports/series 90 cases of exposure to CS and their clinical effects are presented. Their mean age was 25.7 years and 62.0% were males. In addition, 61% of the cases described dermal, 40% respiratory, 57% ocular clinical effects. Life threatening situations as well as long-term health effects were found and were related with exposure to confined/enclosed space. Descriptive and analytical studies have shown attack rates ranging from 12% to 40%. Subjects who were sprayed by the police more often needed special treatment and reported adverse health effects. Apart from transient clinical effects, CS could have lasting and serious effects on human health. Better surveillance of the subjects exposed to CS and completion of cohort studies among exposed populations will illuminate the spectrum of the health effects of exposure to CS.

Riot control agents: the tear gases CN, CS and OC-a medical review

INTRODUCTION

2-Chloroacetophenone (CN), o-chlorobenzylidene malonitrile (CS) and oleoresin capsicum (OC) are common riot control agents. While serious systemic effects are uncommon, exposure to high concentrations may lead to severe complications and even death. The aim of this narrative review is to summarise all main aspects of the riot control agents CN, CS and OC toxicology, including mechanisms of toxicity, clinical features and management.

METHODS

OVID MEDLINE and ISI Web of Science were searched for terms associated with CN, CS and OC toxicity in humans and those describing the mechanism of action, clinical features and treatment protocols.

RESULTS

CN, CS and OC are effective lacrimating agents; evidence for toxicity, as measured by the threshold for irritation, is greatest for CN, followed by CS and OC. Typically, ocular and respiratory tract irritation occurs within 20-60 s of exposure. Ocular effects involve blepharospasm, photophobia, conjunctivitis and periorbital oedema. Following inhalation, effects may include a stinging or burning sensation in the nose, tight chest, sore throat, coughing, dyspnoea and difficulty breathing. Dermal outcomes are variable, more severe for CN and include dermal irritation, bulla formation and subcutaneous oedema. Removal from the contaminated area and fresh air is a priority. There is no antidote; treatment consists of thorough decontamination and symptom-directed supportive care. Ocular exposure requires thorough eye decontamination, an eye exam and appropriate pain management. Monitoring and support of respiratory function is important in patients with significant respiratory symptoms. Standard treatment protocols may be required with patients with pre-existing respiratory conditions. Dermal exposures may require systemic steroids for patients who develop delayed contact dermatitis.

CONCLUSIONS

CN, CS and OC are effective riot control agents. In the majority of exposures, significant clinical effects are not anticipated. The irritant effects can be minimised both by rapid evacuation from sites of exposure, decontamination and appropriate supportive care.

An investigation into the short term and medium term health impacts of personal incapacitant sprays. A follow up of patients reported to the National Poisons Information Service (London)

OBJECTIVES

The aim of this study is to describe the pattern of ill health after personal incapacitant spray (PIS) exposures reported to the National Poisons Information Service-London (NPIS-L) and the Chemical Incident Response Service and to evaluate the relation between sub-categories of PIS exposure and adverse health effects.

METHODS

Case series study of patients reported to the NPIS-L, by attending medical personnel during the period 16 January to 31 September 1998. Data collected by questionnaire sent to these medical personnel.

RESULTS

Several "adverse" symptoms, particularly dermatitis and blisters were reported for cases exposed to police PIS. These cases were more frequent than in those people exposed to non-police PIS. Adverse effects occurring more than six hours after exposure were also observed, which is in conflict with the recorded immediate, short lived, and self limiting symptoms that PIS are designed to cause. Most patients with persisting symptoms required further treatment.

CONCLUSIONS

These findings suggest that the formulation of CS (o-chlorobenzylidine malononitrile) with MiBK (methyl iso-butyl ketone) used by the police is more harmful that has been previously assumed. If confirmed then the continued use of this formulation should be reviewed because of longer duration of adverse effects. Less concentrated formulations may reduce the severity or persistence of the adverse effects.

An update on airborne contact dermatitis

This review is an update of 2 previously published articles on airborne contact dermatoses. Because reports in the literature often omit the term 'airborne', 18 volumes of Contact Dermatitis (April 1991-June 2000), 8 volumes of the American Journal of Contact Dermatitis (1992 1999) and 4 volumes of La Lettre du Gerda (1996-1999) were screened, and the cases cited were classified as to history, lesion locations, sensitization sources, and other factors. Reports on airborne dermatitis are increasingly being published, sometimes in relation to specific occupational areas.

Medical hazards of the tear gas CS. A case of persistent, multisystem, hypersensitivity reaction and review of the literature

A 30-year-old incarcerated man was sprayed with the "tear gas" ortho-chlorobenzylidene malononitrile (CS). He was hospitalized 8 days later with erythroderma, wheezing, pneumonitis with hypoxemia, hepatitis with jaundice, and hypereosinophilia. During the subsequent months he continued to suffer from generalized dermatitis, recurrent cough and wheezing consistent with reactive airways dysfunction syndrome, and eosinophilia. These abnormalities responded to brief courses of systemic corticosteroid but recurred off therapy. The dermatitis resolved gradually over 6-7 months, but the patient still had asthma-like symptoms a year following exposure. Patch testing confirmed sensitization to CS. The mechanism of the patient's prolonged reaction is unknown but may involve cell-mediated hypersensitivity, perhaps to adducts of CS (or a metabolite) and tissue proteins. This is the first documented case in which CS apparently caused a severe, multisystem illness by hypersensitivity rather than direct tissue toxicity. Both the ethics and safety of CS use remain controversial, in part because of the difficulty documenting sporadic injuries received in the field, and also because the charged circumstances surrounding CS use may lead to both underreporting and exaggerated claims of medical harm. The medical literature on CS focuses mainly on its immediate irritant effects and on transient dermal and ocular injuries, with only 2 prior case reports of acute lung injury related to CS exposure. Given the paucity of documented lasting effects despite its widespread use for more than 3 decades, CS appears to be safe when deployed (outdoors) in a controlled manner, but it can cause important injuries if misused or if applied to a sensitized individual.