Bites, Stings, and Pediculosis - 2023 PDF

Bites, Stings, and Pediculosis- Oh My! TARA HIGGINS, PHARMD, BCPPS, FPPA, FFSHP Objectives  Identify exclusions for self care treatment  Compare and contrast clinical presentations and treatments of bites, stings and pediculosis  Describe strategies to prevent bites, stings and pe...

Bites, Stings, and Pediculosis- Oh My! TARA HIGGINS, PHARMD, BCPPS, FPPA, FFSHP Objectives  Identify exclusions for self care treatment  Compare and contrast clinical presentations and treatments of bites, stings and pediculosis  Describe strategies to prevent bites, stings and pediculosis  Apply disease state and therapeutic knowledge to patient case(s) Epidemiology  Very common in outdoor exposure  Local reactions  0.5-3% signs of systemic allergic reactions  In the US more people die of insect stings than bites from all poisonous animals combined  Biting and stinging insect encounters are typically brief  Exception pediculosis and scabies remain on the host until eradicated  10-12 million people in US are affected by pediculosis each year  3-12 years of age is most common Insect Bites Mosquito Bites  Abundantly found worldwide  Humid, warm climates  Vector for spreading infections  West Nile virus, Zika viruses, Chikungunya  20% West Nile infected patients experience flu-like symptoms  Inject anticoagulant saliva into victims  Characteristic welt/itching  Progress to larger blister or urticarial reaction with systemic symptoms  Anaphylaxis is rare Flea Bites  Blood sucking insects found worldwide  Breed best in humid climates  Flea-infested habitat or pets  Multiple bites and grouped  Legs/ankles  Erythematous and intense itching  Transmit diseases  Bubonic plague, endemic typhus Bedbug Bites  Deposit eggs during the day and bite at night  Crevices of walls, floors, picture frames, bedding, folds of linens, corners of suitcases, and furniture  Increased incidence in travelers/hotels  Developing resistance to common pesticides  Expose areas of skin in clusters and may appear in straight line  Head, neck, arms  May take several days to appear  Mild skin irritation to small dermal hemorrhage plus intense itching  Tick Bites  Feed on blood of humans and animals  Mouthparts are introduced into the skin enabling firm hold  Left attached- become engorged and remain for up to 10 days before dropping off  Removed but mouthparts in place- intense itching and nodules requiring surgical excision may develop  Local reaction  Itching papules that disappear within 1 week  Transmission of systemic diseases  Rocky Mountain spotted fever  Headache, rash high fever and extreme exhaustion  Lyme disease  Bull’s eye skin rash (3-30 days after bite) and flu like symptoms  Neurologic symptoms, cardiac disturbances, musculoskeletal symptoms and arthritis Chigger Bites  “Red Bugs”  Live in shrubbery, trees and grass  Myth- burrow and stay there  Attach to skin around edges of tight-fitting clothes  Larvae secrete digestive fluid that causes cellular disintegration, clusters of red papules and intense itching  Fluid causes skin to harden and form tube where chigger remains to feed to engorgement and drops off into an adult Spider Bites  All are venomous but most are unable to penetrate the skin  Exceptions- black widow, brown recluse, hobo spiders  Death is rare but symptoms can be serious  Erythematous lesion, itching, slow healing wound, delayed intense pain  Severe symptoms: muscle spasms, abdominal disturbances, fever, chills, dyspnea, necrotic ulceration Assessment  Spider or tick bites need medical referral  Seriousness of reaction should be evaluated before nonprescription or nonpharmacologic measures are recommended  Exclusions for self-treatment  Hypersensitivity to insect bites resulting systemic symptoms  Less than 2 years of age  History of tick bite and systemic effects indicating infection  Suspected spider bite requiring medical attention  Signs of secondary infection of bite area Treatment Goals  Relieve swelling, pain and itching  Prevent scratching that may lead to secondary bacterial infection  Impetigo  Monitor for infections transmitted by ticks  Prevent future insect bites Non-Pharmacologic Treatment  Avoid insect bites  Application of ice pack wrapped in washcloth 10 minutes on 10 minutes off  Relieve pain/irritation from mosquito, chiggers, bedbugs or flea bites  Avoid scratching  Do not wear rough, irritating clothing over the bite area  Ticks  Remove intact by the head with fine tweezers within 36 hours of attachment  Do not use heating methods- hot nail or match  Do not paint substances on tick- nail polish or petrolatum  After removal clean with rubbing alcohol or wash with soap and water  Save the tick in a sealed bag for future identification Pharmacologic Therapy  Local anesthetics  Topical antihistamines  Counterirritants  Corticosteroids  Skin Protectants  Combination therapies Local anesthetics  Reversible blockade of conduction of nerve impulses at the site of application  Phenol depresses cutaneous sensory receptors  Options are benzocaine, pramoxine, benzyl alcohol, lidocaine, dibucaine, phenol  Apply 3-4 times per day up to 7 days  Relatively nontoxic when applied as directed  Allergic contact dermatitis  Pramoxine and benzyl alcohol less likely to cause adverse effects  Phenol should not be applied extensively or under compresses or bandages due to risk of necrosis of skin  Do not use in children and patients who are pregnant Topical Antihistamines  Exert anesthetic effect by depressing cutaneous receptors  Temporary pain relief of pain and itching from insect bites  Applied 3-4 times per day up to 7 days  Diphenhydramine is most used product  Skin absorption occurs but not sufficient quantities to cause systemic side effects  Caveat is extensive areas and young children  Photosensitivity and hypersensitivity reaction Counterirritants  Apply 3-4 times per day up to 7 days  Camphor  0.1-3% depresses cutaneous receptors causing anesthetic effect which relieves itching and irritation  DO NOT INGEST  Menthol  < 1% depresses cutaneous receptors exerting analgesic effect Corticosteroid  Hydrocortisone 1% indicated for temporary relief of minor insect bites  Apply 3-4 times daily for up to 7 days  Patients with scabies, bacterial infections, or fungal infections should not use without medical supervision Skin Protectants  Act as protectants and tend to reduce inflammation and irritation  Apply as needed up to four times per day  Zinc oxide  Mild astringent and absorbs fluid from weeping lesions  Calamine  Absorb fluid from weeping lesions  Formulations are safe and effective 1-25%  Apply as needed  Recommended for adults, children and infants  Dosage Forms Patient’s preference should guide recommendations Evaluating Patient Outcomes  Follow up after 7 days of self treatment  Seek medical attention if:  Redness, itching or localized swelling worsens during treatment  Develops secondary infection, fever, joint pain, or lymph node enlargement  Symptoms persist beyond 7 days Prevention  Cover as much skin as possible with clothing  Avoid swamps, dense woods and dense brush  Keep pets free of pests  Remove standing water from around home  Limit time spent outside at dawn and dusk  Use window screens and netting  Shower within 2 hours of coming indoors reduces risk of tickborne diseases  Apply insect repellent  Permethrin 0.5% treat clothing and gear Insect repellents  Insect repellents prevent biting insects but not stinging insects  Selection based on ingredients, concentration, formulation, type and length of exposure and patient considerations  N, N-diethyl-m-toluamide (DEET) 5-100% concentrations  Most efficacious repellent  3-[N-butyl-N-acetyl]-aminopropionic acid  Ethyl ester (IR3535)  Picaridin  Plant based  Lemon eucalyptus (OLE), catnip oil, 2-unecanone  Formulations  Pump spray, wipes, aerosol, lotions, towelettes Insect Stings Bee, Wasp, Hornets and Yellow Jacket Stings  Wild honeybees  Mid-west to western US  Barbed stinger remains in skin and injects venom  Venom has greater release of histamine  Paper wasps, hornets and yellow jackets  Southern, central and southwestern US  Yellow jackets most common stinging culprit  Stingers are not barbed, can sting repeatedly Fire Ant Bites/Stings  Imported from South America in 20th century now found in southeastern US  Live in underground colonies  Ant bite symptoms  Sharp pinch, redness and mild swelling at site  Can lead to vesiculation, tissue necrosis and anaphylaxis  Ant sting symptoms  Pain/burning, rednsess/swelling, itching, small bump/blister Clinical Presentation  Occurs 10-15 minutes after sting but no later than 6 hours  Pain  Itching  Irritation  Allergy  Hives, itching, swelling and burning sensation  Anaphylaxis  Rare (3% of adults and 1% children)  Hypotension, light headedness, chest tightness, dyspnea, loss of consciousness  Toxic reaction  Delayed local inflammation 1-2 weeks after sting Assessment  Exclusions for self-treatment  Hives, excessive swelling, dizziness, weakness, nausea, vomiting, difficulty breathing  Significant allergic response away from the site of sting  Previous sting by honeybee, wasp or hornet  Previous severe reaction to insect bites  Personal or family history of significant allergic reactions  Children less than 2 years of age Treatment Goals  Relieve swelling, pain, and itching of insect stings  Monitor any reaction to the sting to determine whether an allergic reaction is developing  Prevent future insect stings Non-Pharmacologic Therapy  Remove stinger and venom sac  Scrape away the stinger with a fingernail or edge of credit card minimizes venom flow  Apply antiseptic after removal of stinger  Hydrogen peroxide  Alcohol  Apply ice pack in 10-minute intervals  Avoid scratching the affected area Pharmacologic Treatment  Same topical options as bites  Oral diphenhydramine  Adults: 25-50 mg per dose  Mild analgesics Severe Allergic Reactions  Avoid future insect stings  Wear bracelet or carry a card  Carry injectable epinephrine  Anaphylaxis  Intramuscular epinephrine  Corticosteroids and antihistamines  Discharge  Anaphylaxis care plan and follow up with allergist Evaluation of Outcomes  Follow up nonallergic reactions to insect stings should occur within 7 days  Seek medical attention  Persistent pain, itching, localized swelling worsens during treatment period or after 7 days of treatment  Symptoms of secondary infection or fever  Follow up for allergic reactions should occur same day if possible Prevention  Avoid wearing perfume and scented lotions  Avoid brightly colored clothes  Control odors in picnic and garbage areas  Change children’s clothing if it becomes contaminated with summer foods  Wear shoes when outdoors  Destroy nests of stinging insects near home Ectoparasites Pediculosis  Pediculus humanus capitis  Head lice  Pediculus humanus corporis  Body lice  Phthirus pubis  Pubic lice Head Lice  Most common lice infestation  Outbreaks common in schools and daycare  Spread through direct head-to-head contact  Sharing personal items unlikely to cause spreading  Affects all socioeconomic groups  Found via visual inspection  Nit is 1 mm in diameter and found within 4 mm of scalp  Louse must begin feeding within 24 hours or it dies  Maturity in 8-9 days  Natural life cycle is every 3 weeks  Bite causes immediate wheal with local papule appearing within 24 hours  Itching may result in secondary infection  Do not transmit infections Body Lice  Live, hide and lay eggs in clothing  Seams and fold of underclothes  Transmit infections like typhus and trench fever  Occurs in individuals who do not shower or change clothes frequently  Homeless Pubic lice  “Crabs”  Transmitted through high-risk sexual contact  Toilet seats, shared undergarments or bedding  Most commonly found in pubic area  Armpits, eyelashes, mustaches, beards and eyebrows Assessment  Visual inspection needed to confirm before treatment  Resistance to treatments reported in region refer to healthcare provider for prescription pediculicide Treatment Goals  Rid the infested patient of lice by killing adult and nymph lice by removing nits from patient hair  Treatment of other family members should be determined on basis of the presence of lice or nits Nonpharmacologic Therapy  Hair combing for nit removal for lice  Wash clothing and bedding in hot water (130F or higher) and dried in clothes dryer  Alternative seal in plastic bag for 2 weeks  Wash combs, hairbrushes and toys in hot water for at least 10 minutes  Carpets, rugs and furniture vacuumed thoroughly and regularly  Not recommended to use insecticidal sprays  Complete head shaving  Body lice controlled through:  Appropriate body hygiene and frequent changing and appropriate laundering of clothing and bed linens  National Pediculosis Association has resources  www.headlice.org  617-905-0176 Pharmacologic Therapy  Synergized Pyrethrins  Permethrin Synergized Pyrethrins  Approved for head and pubic lice  Adverse reactions are cutaneous  Synergized by addition of piperonyl butoxide  Avoid contact with eyes and  Limits ability of lice to break down pyrethrins mucous membranes  Blocks nerve impulse transmission  Do not use if allergic to pyrethrins  Excessive contact time or occlusion of the scalp or chrysanthemums after product application may increase skin  Ragweed sensitive individuals may absorption have cross sensitivity  Applied topically as shampoos, foams, solutions or gels  Do not use in children younger than 2 years  Apply for 10 minutes then rinse or shampoo as recommended  Follow with lice comb  Repeat in 7-10 days  Do not apply more than twice in 24 hours Permethrin  Synthetic pyrethroid  Adverse effects occur in up to 10% of patients  Nonprescription 1% cream rinse/lotion for treating head lice only  Transient pruritis, burning, stinging and irritation of scalp  Disrupts sodium channel, delaying repolarization and causing paralysis  Avoid contact with eyes and and death of parasite mucous membranes  Application instructions  Contraindicated in patients sensitive to pyrethrins or  Cover or saturate washed hair and chrysanthemums scalp with sufficient quantities  Leave in for 10 minutes before rinsing  Should not be used on infants younger than 2 months  Comb with lice comb  Retreatment in 7-10 days is not required unless active lice detected Evaluation of Outcomes  Follow up should occur within 10 days  Seek medical attention for:  Significant skin irritation or excessive exposure to eyes or mucous membranes  Symptoms of lice infestation after second treatment  Resistance to pyrethrins or permethrin has been reported in the region Prevention  Avoid close, physical contact with infested individuals  Do not share combs, brushes, towels, caps and hats with infested persons Summary  Majority of treatment for bites, stings and pediculosis is non- pharmacologic and non-prescription medications  It is important to recognize those patients who require being seen by a medical provider Questions References  Chapter 37: Insect Stings and Bites and Pediculosis. Handbook of Nonprescription Drugs: An Interactive Approach to Self-Care, 20th edition.  Ogbuefi N and Kenner-Bell B. Common pediatric infestations: update on diagnosis and treatment of scabies, head lice and bed bugs. Curr Opin Pediatr 2021; 33:401-415.  Pansare M, Seth D, Kamat A, et al. Summer Buzz: all you need to know about insect sting allergies. Pediatr Rev 2020; 41(7):348-356.