Browntail Moth and the Big Itch: Public Health Implications and Management of an Invasive Species July 22, 2021 Jill H. Colvin, MD, FAAD MDFMR Dermatology photo credits: Jon Karnes, MD Thomas E. Klepach, PhD Assistant Professor of Biology, Colby College Ward 3 City Councilor, Waterville, Maine Financial disclosure statement Jill H Colvin MD and Thomas E. Klepach, PhD do not have a financial interest/arrangement or affiliation with any organizations that could be perceived as a conflict of interest in the context of this presentation. OBJECTIVES • Identify: • Impacts of browntail moth (BTM) infestation on humans and the environment • Review: • Presentation and treatment of BTM dermatoses • Biology of the BTM • Population trends of the BTM • BTM mitigation strategies JUNE 2021, AUGUSTA, MAINE PERVASIVE! COMPLICATIONS OF INVASIVE BROWNTAIL MOTH SOCIAL MEDIA RADIO ARBORISTS PHARMACY NEWSPAPERS FRIENDS COLLEAGUES HEALTH CARE FAMILY TEXTS TOURISM PATIENTS MAINE.GOV SELF REALTY PHONE CALLS ACTIVISM TREES SOCIAL MEDIA IMPACT: TOURISM, REAL ESTATE, DAILY LIFE Maine.gov Maine.gov Photo credit: Jon Karnes, MD Photo credit: Robert Kenney, DO BTM: Risk to Human Health Mediated by: Toxic hairs on caterpillars, female moths, environment Direct contact Airborne Damage skin, eye, airway in multiple ways Mechanical: Barbs on hair Chemical: toxin Irritant Allergen One report of Death – 1914: ”severe internal poisoning caused by inhaling the hairs” Definitions Lepidopterism is the term for cutaneous and systemic reactions that result from contact with larvae (ie, caterpillars) or adult forms of moths and butterflies (order, Lepidoptera). Erucism (from Latin "eruca," caterpillar) is also used to refer to reactions from contact with caterpillars. photo credit: Jon Karnes, MD “The BTM, its caterpillar and their rash” Clinical and Experimental Dermatology (1979), Cicely P. Blair, Oldchurch Hospital, Essex, England 36 patients, 4 – 76 years old • “Not all patients knew they had been in contact w/ caterpillars but knew that there were caterpillars in vicinity.” • The vicinities were examined to confirm presence. Interval between exposure and symptoms: 8 – 12 hours • Except for one patient w/“blotchy erythema” few minutes post exposure Symptoms: itching > > soreness • peaks during first 24 hours, resolves over 10 days Associated findings: • Conjunctivitis (2 patients) resolved within 5 weeks • Malaise thought due to antihistamines or lack of sleep (3 patients) Photo credit: Jon Karnes, MD • Rhinitis ? Due to seasonal allergies as prick test was negative to caterpillar molt (1 patient) • Dry cough x 1 week coincidental with rash (1 patient) • Secondary impetigo (1 patient) BTM Rash: • Neck, wrists and forearms > other noncovered areas • Day 1 – 3: 3 – 5 mm red maculo-papules which may be tinged with orange centrally • Sometimes had vesicle or pustule • Lesions were larger and could be linear if direct caterpillar contact occurred • Resolved within 10 days • Though can last longer, typically via re-exposure. • “One patient and the eruption for 4 months and had burned his duvet and was on the point of destroying his Siamese cat before establishing BTM as etiology.” Photo credit: Jon Karnes, MD Investigative Studies of the Dermatitis Caused by the Larva of the BTM Arch. Derm. Res. (1976) deJong, et. al., Dept. Derm., State University Groningen (The Netherlands) Hypothesis: Inflammatory reactions due to at least two effects • Mechanical trauma from the barbed setae (hairs) • Toxic actions of water-soluble substances associated with setae Histopathology of skin after nettling hairs into skin (39 biopsies) • Untreated hairs > trauma to skin than heat treated hairs Scanning Electron Microscopy of Setae (hairs) • Tapering hollow microcapillaries which are open at both ends • May serve as microneedles which liberate irritant substances • Mechanical and toxic effects Caterpillars and Moths Dermatologic Therapy, 2009 Eric W. Hossler, Dept. Derm. Geisinger Medical Center, Danville, PA “Therapy remains largely empiric; to my knowledge there have been no controlled therapeutic trials for lepidopterism.” • “Home remedies can help with symptoms.” • RX approaches for BTM contact dermatitis can help, but not as reliably as we expect for classic allergic contact dermatitis • Topical steroids • Prednisone tapers Treatment Strategies Remove offending hairs from skin • Duct tape or other adhesive • Immediate washing with soap and water • Shower not tub bath • Change and launder clothing • Remove jewelry and watches in anticipation of swelling Relieve symptoms of itch • Camphor, menthol, pramoxine, cool packs, witch hazel, topical diphenhydramine Reduce inflammatory reaction • Topical steroids • Systemic steroids • prednisone 1 mg/kg/day tapered over 2 – 3 weeks • IM Triamcinolone 40 mg • Systemic antihistamines: variably helpful • Topical aspirin reduced histamine induced itch in one study Prevention/avoiding exposure • Protective clothing, mask, do yard work on wet days • Dry clothes inside not outside on a line If you are having trouble breathing, swallowing, or have swelling of your mouth tongue, or throat, call 911. RareRare systemicsystemic riskrisk fromfrom BTM:BTM: PulmonaryPulmonary ? AnaphylacticAnaphylactic OneOne reportedreported deathdeath inin thethe earlyearly 1900s1900s afterafter BTMBTM setaesetae inhalationinhalation Photo credit: Jon Karnes, MD State Resources • Maine.gov • 211, text 898211 • ME Dept. of Agriculture, Conservation and Forestry ME Forest Service Entomologists + U Maine Track spread Investigate causes Evaluate management strategies https://www.centralmaine.com/2021/06/02/waterville-council-exploring-ways-to-mitigate-browntail-moth-infestation-in-the-city/ Browntail Moth: Public Health implications & Management Dr. Thomas Klepach, PhD, Assistant Professor Biology Department Colby College, Waterville City Council Ward 3 Representative Seals of The City of Waterville and Colby University in 1896 when BTM Were First Reported in the US Browntail Moth: Public Health implications & Management Dr. Thomas Klepach, PhD, Assistant Professor Biology Department Colby College, Waterville City Council Ward 3 Representative Objectives: • Biology • Pathogenesis • History • Causative and Mitigating Factors in Outbreaks • Management Strategies & Policy Recommendations Euproctis: genus of >650 named moths native to eastern hemisphere 1. E. similis - Goldtail moth or Swan moth (Eurasia, Ural Mountains etc.) 2. E. edwardsi – Mistletoe browntail moth (Australia) A half dozen species 3. E. bipunctapex –Tussock moth (Singapore, Thailand) from this genus are a 4. E. flava – Asian mulberry tussock moth (Japan, China) health hazard to 5. E. pseudoconspersa – Japanese tea tussock moth (Japan) humans and animals. 1 2 3 4 5 Euproctis: genus of >650 named moths native to eastern hemisphere 1. E. similis - Goldtail moth or Swan moth (Eurasia, Ural Mountains etc.) 2. E. edwardsi – Mistletoe browntail moth (Australia) A half dozen species 3. E. bipunctapex –Tussock moth (Singapore, Thailand) from this genus are a 4. E. flava – Asian mulberry tussock moth (Japan, China) health hazard to 5. E. pseudoconspersa – Japanese tea tussock moth (Japan) humans and animals. 1 2 3 4 5 Part of the family Lymantriidae that includes the gypsy moth (Lymantria dispar), another non-native urticarial moth. Euproctis: genus of >650 named moths native to eastern hemisphere 1. E. similis - Goldtail moth or Swan moth (Eurasia, Ural Mountains etc.) 2. E. edwardsi – Mistletoe browntail moth (Australia) A half dozen species 3. E. bipunctapex –Tussock moth (Singapore, Thailand) from this genus are a 4. E. flava – Asian mulberry tussock moth (Japan, China) health hazard to 5. E. pseudoconspersa – Japanese tea tussock moth (Japan) humans and animals. 1 2 3 4 5 6. E. chrysorrhea – European browntail moth (Eurasia, Maine) Ecologically unannealed xenobiotic species with few native biological controls that poses a direct human health threat. 6 Female Brown-tail Moth (Euproctis chrysorrhoea) Alvesgaspar, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5027960 Brown-tail Moth Life Cycle Diapausal Overview: Terminology larvae (nesting) Larvae – caterpillars Pupae – cocoon phase Imago – adult moth Diapause – nesting caterpillars Gregarious – feeding together Dispersive – feeding separately Instar – larval moult Setae – invertebrate “hair” Brown-tail Moth Life Cycle Diapausal E. Chrysorrhoea spends 9 months in a larvae (nesting) larval (caterpillar) form. Brown-tail Moth Life Cycle Diapausal E. Chrysorrhoea spends 9 months in a larvae (nesting) larval (caterpillar) form. Only 3 feeding months in Maine. Brown-tail Moth Life Cycle Diapausal E. Chrysorrhoea spends 9 months in a larvae (nesting) larval (caterpillar) form. Only 3 feeding months in Maine. Peak hair exposure is in late spring and summer Brown-tail Moth Life Cycle Egg Female Brown-tail Moth oviposting. The eggs are hidden under the brown, felt-like covering. Aug. – Sept. Egg masses contain 200 to 400 eggs. When the larvae hatch they feed for a short time before building their winter nests Prefer non-current-year-defoliated trees for laying eggs. Brown-tail Moth Life Cycle Egg Brown-tail moth egg mass develops over roughly 1 month. Aug. – Sept. Egg masses contain 200 to 400 eggs. When the larvae hatch they feed for a short time before building their winter nests Brown-tail Moth Life Cycle Egg Brown-tail moth caterpillars emerging from the egg mass. Aug. – Sept. Egg masses contain 200 to 400 eggs. When the larvae hatch they