Wilderness Section Newsletter: Fall 2026

In this issue:

• Climate-Driven Shifts in Toxic Mushroom Exposure
• Case Report: Oyster Shell Lacerations: Antibiotics and Pediatric Population Considerations

Climate-Driven Shifts in Toxic Mushroom Exposure

Devin R Sandlin, MD

In a Northern California ED, a young, previously healthy couple presents with jaundice, coagulopathy, and markedly elevated liver enzymes. Review of the medical record reveals a recent ED visit for severe vomiting and diarrhea beginning several hours after a foraged mushroom meal. Having identified the mushrooms as edible using a smartphone application, they’re ultimately diagnosed with amatoxin poisoning from Amanita phalloides, part of an uncharacteristically large regional bloom that caused more than a dozen poisonings in just two weeks.

Mushroom toxicity has historically been a somewhat predictable problem in emergency and wilderness medicine. Most exposures involve patients, often young children, with mild gastrointestinal illness during defined seasonal windows. That pattern is changing. Climate shifts, globalization, and new foraging behaviors are reshaping where, when, and how toxic exposures occur.

Most of the nearly 10,000 annual reports of mushroom exposures are benign. In the United States, the total number of reported cases has remained stable. However, significant changes in exposure patterns have been observed. Climate change is significantly affecting toxic mushroom distribution, growth patterns, and poisoning incidence through multiple mechanisms including altered temperature and precipitation patterns, geographic range expansion of toxigenic species, and increased mushroom fruiting during favorable meteorological conditions. Fungi respond quite rapidly to environmental changes. With that, toxic species are moving northward and to higher elevations, exposing foragers and physicians to unfamiliar risks. Heavy rain after drought, wildfires, and other environmental phenomena can trigger sudden mushroom proliferation. Classic teaching (spring Gyromitra, fall Amanita) is becoming less reliable. Warmer temperatures are extending fruiting seasons and blurring these distinctions. The opening vignette, based on a large 2016 San Francisco Bay Area bloom, illustrates how these short-lived blooms can produce clusters of severe poisoning. Brought on by a warm spell with abundant rainfall, this event resulted in at least two dozen clinically significant poisonings with three patients requiring liver transplants.

In some areas of the world, ingestion of poisonous mushrooms has emerged as the most common cause of foodborne illness outbreak. One such area is Chongqing, China, where toxic mushrooms are implicated in more than double the number of outbreaks of the second-place contender (meat and meat products), and are also to blame for the most fatalities. Foraging is common in China, and therefore surveillance is comparatively robust. In addition to case identification, these programs have identified emerging toxic species such as Amanita molliuscula and relatives A. exitialis and A. fuliginea, all of which have been implicated in clusters of severe hepatotoxicity.

For clinicians, these evolving patterns can be a diagnostic challenge. Exposures are becoming less predictable in timing, geography, and clinical presentation, and new or previously unrecognized or underreported toxic species continue to emerge. Overreliance on seasonality, location, and especially attempted identification should be avoided. Instead, clinical fundamentals remain the mainstay: careful and thorough history including symptom timing, consideration of delayed toxicity, treatment of underlying pathophysiology, and recognition of toxidromes.

Case Report: Oyster Shell Lacerations: Antibiotics and Pediatric Population Considerations

Authors

Emily Jordan Bush, BS
Shea Cheney, MD
Kaitlyn Yatson, PA-C

Key Words

Vibrio Vulnificus, Oyster Laceration, Pediatrics, Marine Injuries

Consent

Consent was obtained from both the patient's parents.

Abstract

This case report summarizes the assessment and treatment plan of a pediatric patient who sustained a laceration from an oyster shell. The patient presented to a local pediatric emergency department with an uncomplicated laceration to the forearm after falling into an oyster bed in the Southeastern Coastal area. The wound was cleaned and repaired in the ED and the patient was placed on a multi-antibiotic regimen. The patient tolerated the procedure well and the wound healed without complications or infection. This case outlines special considerations for antibiotic selection in pediatric patients with wounds sustained from marine injuries.

Introduction

Marine injuries require careful consideration for wound care and antibiotic selection. Lacerations sustained in a marine environment or from aquatic creatures must be treated as high-risk for complications due to the physical characteristics of such wounds and contamination with bacteria specific to marine environments.

The wounds sustained from oyster shells are unique injuries. Oyster shells tend to be both sharp and fragile, easily leaving shell fragments in the wound. The sharpness of the shell often leads to deep lacerations, and the wound is immediately inoculated with marine bacteria such as Vibrio Vulnificus.¹ Such bacteria may cause rapid and serious infection, such as wound abscesses and, in more severe cases, necrotizing fasciitis.¹

Antibiotic coverage should be directed at treating V. Vulnificus. In this case, the oyster was located in the southeastern coastal area, which harbors bacteria that live in brackish water.

Furthermore, as with any laceration, especially those with a high likelihood of contamination, an up-to-date tetanus vaccine is exceedingly important.

Selection of wound closure techniques should be based on the characteristics of the wound, with a low threshold to leave the wound to heal by secondary intention when the risk of infection is high. If the wound involves deep tissues, is gaping, or would have poor cosmetic outcomes due to the body area involved, wound closure should be considered.² Otherwise, there is no wide consensus on primary closure versus delayed primary wound closure.

It is important to note that directed antibiotic coverage may present challenges in the pediatric population. Several first-line antibiotics present adverse side effect profiles in children, and the risks versus benefits of administering such medications should be weighed prior to selection. Risks of complications may increase in the pediatric population due to potential delayed reporting or unreliable history if given by the child, as well as limitations in antibiotic selection due to increased side effect risk profile in children.

Case

A previously healthy 22-month-old male presented to the pediatric emergency department with a laceration to the right forearm after falling into an oyster bed. The patient is up to date on vaccinations, including Tetanus. Vital signs, including heart rate, respiratory rate, temperature, and oxygen, were age-appropriate. Physical examination revealed an active, well-appearing child in no acute distress with a 3 cm laceration to the posterior right forearm with no foreign body or deep structure involvement. Tendon exam of the right arm showed no functional deficit with full range of motion. No X-ray was performed given no concern for fracture or retained foreign body. For wound repair, extensive irrigation with saline was performed, and chlorhexidine skin preparation was used; LET topical gel was used for local anesthesia. The wound was thoroughly explored in a bloodless field, and no retained foreign bodies were visualized. The laceration was closed with 3 simple interrupted sutures of 4-0 nylon, with loose approximation, and dressed with Bacitracin antibiotic ointment. The patient received intramuscular Ceftriaxone at 50 mg/kg (565 mg) and one dose of intramuscular trimethoprim-sulfamethoxazole. The patient was discharged with instructions to return in 24 and 48-hours for two more doses of 50 mg/kg and to re-examine the wound. The patient was prescribed oral TMP-SMX twice daily at home for a 7-day regimen. A follow-up was arranged for 7 days to remove the sutures. The patient had a favorable outcome, with the wound healing well without infection or complications.

Discussion

This case illustrates special circumstances that must be considered to prevent infection and wound complications in marine injuries. The pediatric population often presents unique challenges, such as potential for unreliable history, delayed reporting, and limitations in antibiotic regimen selection and compliance. These factors should be considered when treating lacerations sustained in a marine environment in the pediatric population. This case summarizes a treatment plan that includes age-specific considerations for increased infection risk. According to the CDC, children can be treated with a third-generation cephalosporin plus doxycycline or a fluoroquinolone, or an alternative combination of trimethoprim-sulfamethoxazole and an aminoglycoside.³ In this case, doxycycline and a fluoroquinolone were ruled out due to their side-effect profiles and the patient’s age. Thus, combination therapy with trimethoprim-sulfamethoxazole and ceftriaxone was chosen. Wound care strategies in marine-associated lacerations should include thorough irrigation and exhaustive wound exploration with careful removal of contaminants and foreign bodies. Imaging may aid in these cases, as tiny shell fragments may be retained quite easily. Primary closure should be avoided when able, but if necessary, the wound should be repaired in loose rather than close approximation with an interrupted suture technique to prevent infection. Appropriate antibiotic selection is essential for favorable outcomes, given the tendency of saltwater bacteria to cause rapid, serious infections, and careful consideration of the risks versus benefits of administering certain preferred antibiotics in the pediatric population. The importance of antibiotic compliance and diligent follow-ups for wound checks should be communicated to patients and families/caregivers. Marine-associated lacerations in pediatric patients require careful evaluation due to the risk of infection with saltwater pathogens. Early and thorough irrigation, appropriate antibiotic coverage, and close follow-up are critical to preventing complications.

Conclusion

Marine-associated lacerations in pediatric patients require careful evaluation due to the risk of infection with saltwater pathogens. Early and thorough irrigation, appropriate antibiotic coverage, and close follow-up are critical to preventing complications.

References

1. Diaz JH. Skin and Soft Tissue Infections Following Marine Injuries and Exposures in Travelers. Journal of Travel Medicine. 2014;21(3):207-213.
2. Baddour, MD, FIDSA, FAHA LM. Soft Tissue Infections following Water Exposure. Uptodate.com. Published 2026. Accessed May 2, 2026. 
3. CDC. Clinical Overview of Vibriosis. Vibrio Infection (Vibriosis). Published May 16, 2024. Accessed May 1, 2026.