Tropical immersion foot

Prevention and Treatment of Nonfreezing Cold Injuries and Warm Water Immersion Tissue Injuries: A Supplement to the Wilderness Medical Society Clinical Practice Guidelines

We convened an expert panel to develop evidence-based guidelines for the evaluation, treatment, and prevention of nonfreezing cold injuries (NFCIs; trench foot and immersion foot) and warm water immersion injuries (warm water immersion foot and tropical immersion foot) in prehospital and hospital settings. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. Treatment is more difficult with NFCIs than with warm water immersion injuries. In contrast to warm water immersion injuries that usually resolve without sequelae, NFCIs may cause prolonged debilitating symptoms, including neuropathic pain and cold sensitivity.

Human vulnerability and variability in the cold: Establishing individual risks for cold weather injuries

Human tolerance to cold environments is extremely limited and responses between individuals is highly variable. Such physiological and morphological predispositions place them at high risk of developing cold weather injuries [CWI; including hypothermia and/or non-freezing (NFCI) and freezing cold injuries (FCI)]. The present manuscript highlights current knowledge on the vulnerability and variability of human cold responses and associated risks of developing CWI. This review 1) defines and categorizes cold stress and CWI, 2) presents cold defense mechanisms including biological adaptations, acute responses and acclimatization/acclimation and, 3) proposes mitigation strategies for CWI. This body of evidence clearly indicates that all humans are at risk of developing CWI without adequate knowledge and protective equipment. In addition, we show that while body mass plays a key role in mitigating risks of hypothermia between individuals and populations, NFCI and FCI depend mainly on changes in peripheral blood flow and associated decrease in skin temperature. Clearly, understanding the large interindividual variability in morphology, insulation, and metabolism is essential to reduce potential risks for CWI between and within populations.

Distal limb pathologic conditions in horses treated with sleeve-style digital cryotherapy (285 cases)

Digital cryotherapy (DC) is frequently used as laminitis prophylaxis for horses. While DC with ice-water slurries is reported to be safe for up to 48 h, the safety of sleeve-style digital cryotherapy (SSDC) with ice in direct contact with the distal limb has not been evaluated. Our objective was to determine the incidence of distal limb pathologic conditions (DLPC) among horses treated with SSDC. A retrospective study of cases from 2011 to 2015 identified 285 horses treated with SSDC for a minimum of 12 h. Data collected from medical records included demographic, treatment, diagnostic, and SSDC treatment parameters. Bivariate statistics and a generalized linear regression model were created to evaluate risk factors associated with increased incidence of DLPC. Among horses treated with SSDC, 7% had tissue injury of the distal limb. Increasing duration of SSDC was associated with increased incidence of DLPC. Lesions observed included dermatitis, cellulitis, alopecia, coronitis, tissue necrosis, and distal limb edema. These lesions were similar to frostbite, non-freezing cold injury, and prolonged water immersion injuries seen in other species. While the incidence of DLPC was low, the authors recommend that horses undergoing SSDC with ice in direct contact with the skin should be monitored closely for injury when prolonged cryotherapy is clinically indicated. Further studies to improve safety, efficacy, and convenience of alternative methods of DC for horses are warranted.

Warm-water immersion foot among car wash workers

Background

Warm-water immersion foot (WWIF) is associated with prolonged contact with water at high temperature. Car wash workers are frequently exposed to humidity, however, there are not studies targeting diseases affecting this category of employees.

Objective

To investigate the frequency of WWIF among car wash workers.

Methods

The study was carried out in 2013 at a car wash service in Jundiaí, São Paulo, Brazil. A group of 30 workers was subjected to clinical interview and dermatological examination. Statistical tests were performed to assess the association between WWIF and independent variables.

Results

All the participants were male, their average age was 23 years old, and the most (60%) had worked at the investigated company for more than one year. Sixty percent of the participants exhibited lesions compatible with WWIF. Age and length of work at the company were associated with the assessed outcome. The participants were frequently and permanently exposed to humidity along the working day without wearing impermeable clothes.

Conclusion

Most participants exhibited WWIF; the ones over 30 years old and having worked less than 1 year at the investigated company exhibited higher odds of WWIF due to occupational exposure to humidity.

An unusual case of an immersion hand presentation in a military signaller operating in the jungle in Belize

Belize, hosting one of the British Army's overseas training areas, provides access to challenging terrain and austere environments, which allows the delivery of training to soldiers on survival and combat within the jungle environment. A 26-year-old infanteer on exercise in Belize presented with progressive bilateral dry, painful, oedematous hands, secondary to the harsh environmental conditions of the jungle and inadequate drying of his hands resulting in his inability to perform his combat duties. The symptoms completely resolved with drying, emollient application and analgesia. While there are no reported cases of immersion hand, comparisons can be made with the well-reported warm weather immersion foot. This case highlights the importance of force preparation and soldier education for units deploying to the jungle. Simple preventive measures, including adequate 'wet-dry' drills and use of emollients can reduce the prevalence of immersion hand, a preventable condition, which can have a significant impact on the overall combat effectiveness of the unit.

Skin microbiome: looking back to move forward

Trillions of bacteria, fungi, viruses, archaea and small arthropods colonize the skin surface, collectively comprising the skin microbiome. Generations of researchers have classified these microbes as transient versus resident, beneficial versus pathogenic, collaborators versus adversaries. Culturing and direct sequencing of microbial inhabitants identified distinct populations present at skin surface sites. Herein, we explore the history of this field, describe findings from the current molecular sequencing era, and consider the future of investigating how microbes and antimicrobial therapy contribute to human health.

Environmental skin diseases and the impact of common dermatoses on medical readiness

The environmental extremes in which soldiers exercise and fight, like the environmental extremes in which many civilians encounter occupationally and recreationally, can prove to be a significant cause for morbidity and decreased effectiveness. A variety of skin diseases are related to occupational exposure to dusts and ultraviolet radiation as a well known cause of cutaneous damage. As more is understood about the biochemical factors involved in frostbite injury, treatment recommendations have changed. Too much water, hot or cold, is a continued source of cutaneous misery to the soldier in the field. Finally, even common minor skin ailments can incapacitate the sufferer when confronted with unfavorable environments.

Hydration and occlusion treatment for hypertrophic scars and keloids

In 31 patients with hypertrophic scars or keloids, a side by side test was carried out to check the efficacy of an occlusive dressing technique using cream which did not contain silicone oil, versus a simple application of vaseline, used as a control. In all cases, the cream treated areas of scar and keloid demonstrated a remarkable improvement over that of the vaseline treated area. These findings strongly suggest that the mechanisms of hydration and occlusion are the main basis of the therapeutic action of this method in treating hypertrophic scars and keloids.

Moon-boot foot syndrome

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Effects of prolonged continuous exposure of human skin to water: a reassessment

Continuous exposure of human skin to water in small plastic cups for periods of 72 and 144 hr produced a mild, transient dermatitis in half the sites tested. The degree of dermatitis was only slightly greater at 144 than at 72 hr, and was unrelated to the pH of the water samples. Comparison of soap-pretreated to non-pretreated skin areas showed a significant tendency for the more severe dermatitis to be present on the non-pretreated skin areas at higher pH's. There was virtually no coating of hairs with waxy yellowish material (clumps of bacteria), and no lesion was produced that resembled warm-water-immersion injuries.