Summer's Finale: Stings, Bites, Mites, and Lice

Retail health clinicians should be armed with the knowledge of how to treat what could be more than just a minor skin irritation.

Summer’s activities can elicit childlike excitement across the lifespan! Amid the adventure of outdoor fun, however, lurks the irritation and potential danger of insect bites and stings.

For most children, bug bites or stings are only minor irritations. For a small percentage of children, however, the danger of larger local or even serious systemic reactions is a possibility. For the retail health care provider, getting children ready for the first day of school may include evaluating summer’s lingering maladies to allow young students to be at peak performance.

Most insect bites result in a local inflammatory reaction triggered by the insect’s salivary proteins. The reaction begins soon after the bite, with local itching, swelling, and redness. Symptoms usually subside in a few hours without sequelae. Some bites can produce more severe local tissue reactions, papular urticaria, serum sickness, systemic allergic reactions, secondary bacterial infections, or transmission of a pathogen that can cause other diseases.

Mosquito bitestypically produce immediate swelling and erythema. This minor reaction generally peaks in 20 minutes, but pruritus and indurated papules may peak in 24 to 36 hours, resolving over 7 to 10 days. A larger local allergic reaction consists of pruritic, red, warm, swollen lesions ranging from 2 to 3 cm up to 10 cm or more in diameter. Sometimes known as “skeeter syndrome,” this reaction is most common in young children who have no natural immunity to mosquitoes. This type of reaction can involve larger surfaces and interfere with use of the affected extremity or with vision, eating, or drinking. Systemic symptoms of malaise and fever may also be experienced.

Differentiation between allergic inflammation and inflammation caused by secondary bacterial infection postscratching can be difficult. A careful history of the site appearance in relation to the timing of the bite is helpful. Skeeter syndrome begins within hours, sometimes with the development of ecchymosis, blisters, vesicles, or bullae. Urticaria, anaphylaxis, serum sickness, lymphadenopathy, hepatosplenomegaly, fever, and necrotic skin reactions are other possible systemic allergic reactions. Secondary bacterial infections begin within days. Skeeter syndrome reactions generally subside after a few years in otherwise healthy children.

Treatment of the larger local reactions include antihistamines and, if severe, glucocorticoids. Prevention includes mosquito avoidance and prophylaxis with nonsedating H1 antihistamines. Mosquitoes are attracted to human body odor, skin temperature, and exhaled carbon dioxide.¹Patient education includes avoidance of outdoor activities at dawn and dusk, wetlands, bush, and tall grass. The elimination of standing water (ie, reduction of the breeding habitat), as well as screens on windows and doors can decrease the risk of mosquito bites around the home. A variety of insect repellents safe for children are available commercially.²

Vectors of infectious diseases transmitted by mosquitoes in the United States include parasitic and viral illnesses (eg, West Nile virus, St. Louis and La Crosse encephalitis). Worldwide, malaria, yellow fever, dengue hemorrhagic fever, and chikungunya fever (recently reported in the United States) are also transmitted by mosquitoes. Diagnosis and treatment of these diseases will not be discussed here.³

Tick bitesare of particular concern due to the possibility of serious reactions and transmission of infectious diseases. In the United States, these diseases include Lymeborreliosis(Eastern, North Central, and Western regions), Rocky Mountain spotted fever (Eastern and South Central regions), erlichiosis, babesiosis, and tularemia. In children with witnessed tick bite or removal and suspected infectious disease transmission, symptoms include a characteristic “bull’s eye” rash, fever, fatigue, headache, stiff neck, and body aches. Rare allergic reactions to some tick bites have occurred. Treatment of local reactions includes antihistamines and anaphylactic precautions. Further diagnosis and management of tick-borne diseases are not discussed here.

Fly bitescan cause allergic reactions and transmit infectious diseases. Blackflies, horseflies, deerflies, and sandflies are examples of flies capable of inducing allergic and inflammatory reactions, including anaphylaxis. Houseflies have been implicated in the transmission of enteric infections.³

Flea bitescan be a mere annoyance or can produce papules or papular urticaria. Flea bite clusters do not follow follicular distribution and frequently occur on the legs.⁴Although flea bites can sometimes induce respiratory symptoms (especially in children with a cat allergy), anaphylaxis has not been reported. Fleas, in association with animals and humans, can assist in the transmission of infectious agents as part of their life cycle. Some of these include plague, bartonellosis, typhus, and tungiasis.³

Chigger bitescome from the larvae of a mite (Trombiculidaefamily). There are a number of aliases for these arachnids (eg, harvest mites, bugs, lice, Mower’s mites, and redbugs). The larvae of these mites live on leaves or grass, waiting patiently for any contact with animal or human hosts. Chiggers remain on their host only a few days. Trombiculid mites enjoy moist and thin skin sites; they wander from their initial exposed skin contact site seeking prime feeding sites. Belts or elastic waistbands stop the chigger’s migration, frequently resulting in clustering of bites in these areas. The mites secrete digestive enzymes that liquefy epidermal cells, which is the perfect larvae meal. These enzymes are inflammatory to human skin, resulting in the classic clinical features of inflammation and pruritus. Significant pruritus begins within hours after the bite and lasts a few days, and the lesions resolve in 1 to 2 weeks. However, reports of skin eruptions and pruritus persisting for weeks have been noted.

Sleep can be difficult for the child with extensive involvement and intense pruritus. Although papular and papulovesicular skin reactions are typical, pruritic red macular rash and bullous eruptions can occur. Differential diagnoses include other insect bites, contact dermatitis, and pemphigoid (with pronounced bullae). Diagnosis is based on a history of recent outdoor activities in a chigger habitat, as well as reported pruritic grouped papules, papulovesicles, or bullae over the ankles, waistline, or other areas. Cleansing skin and clothes with soap and water can help remove any lingering mites.

Managing pruritus with cool compresses, topical antipruritics (hydrocortisone, pramoxine, calamine), and/ or oral antihistamines is effective.⁵Prevention includes avoiding chigger habitat (grasslands, forests, lakes or streams), keeping trousers tucked into socks, and applying insect repellant on skin or clothes prior to exposure.⁶

Stingsdiffer from bites due to the insect’s puncturing/stinging device and subsequent venom injection. Local irritation and life-threatening systemic reactions are possible. Honey and bumble bees, yellow jacks, wasps, and otherHymenopteragenerally sting in self-defense or protection of their nest or hives. Because these are painful, the sting is usually noticed even if the insect is undetected. Lesions that result from these stings are similar in appearance, so environmental setting, geographic location, and nest appearance may assist in identification of the offending insect when necessary for follow‑up treatment.

Typical reactions to insect stings include uncomplicated local tissue symptoms of erythema, edema (about 1 to 5 cm), and pain at the sting site. This reaction begins within minutes and resolves in a few hours. Approximately 10% of persons, however, experience amplified redness and swelling, with subsequent involvement up to 10 cm in diameter. This larger, uncomplicated local tissue reaction usually peaks in 48 hours and resolves slowly over 5 to 10 days. Rarely, superinfections occur. Infection should be a consideration if fever develops or when pain, redness, and swelling dramatically worsen 3 to 5 days after the sting.⁷

General first aid for mild reactions to insect bites and stings includes washing the area with soap and water; removing any stingers; applying cool compresses, topical cortisone, lidocaine, calamine lotion, colloidal oatmeal, or baking soda; and using OTC oral antihistamines.⁵

Bedbugshave been increasingly noted in hotels, theaters, workplaces, dorms, and schools. These small (1-7 mm), flat, reddish-brown, wingless insects hide in cracks and crevices of mattresses, cushions, bedframes, and other walls or furniture. Bites from bedbugs can result in substantial psychosocial distress and allergic reactions. Bedbugs are rarely seen and commonly bite painlessly at night. A child may awaken or notices bites after several days. Presentations range from itchy macules to erythematous, maculopapular, pruritic lesions, orwhealswith central hemorrhagic punctum. More severe reactions include urticaria or bullae. Lesions usually resolve in 1 week. Impetigo or cellulitis may be secondary infections. Differential diagnoses include bites from other arthropods, scabies, fleas, or parasitic mites.

Good hygiene is recommended, and management of pruritus with topical corticosteroids and/ or oral antihistamines is helpful. Careful inspection of bedding and furniture to avoid contact and storage of clothes or bedding in a closed container off the floor can help reduce exposure. Eradication can be difficult, even with professional pest management. Insecticides, vacuuming, laundering, and freezing infested articles can assist eradication efforts.⁸

Spider bitesare rare, and only a handful of spiders cause problems in humans. Most spiders are incapable of penetrating human skin and, therefore, pose no threat. Bites from widow spiders, recluse spiders, and yellow sac spiders found in North America can be medically significant, however. Bites are usually solitary papules, pustules, or wheals. Local redness with a tender nodule at the site occurs within minutes. Small puncture marks may also be visible. Pain may be noted at the sight.

Most local reactions resolve independently in about 7 to 10 days. Secondary infections are possible. Necrosis is an uncommon complication, even with recluse spider bites. If sufficient volume of widow spider venom enters the circulation, systemic reactions can occur. Allergic reactions are rare, and typically occur due to contact with spiders versus bites. Diagnosis of a spider bite is definitive when a direct bite is observed and the spider collected and properly identified. All other diagnoses of spider bites are presumptive, based on history and presentation.

Spider bite diagnoses should be excluded if there are multiple or widely- separated lesions, or when multiple occupants of the same household are simultaneously affected. Infections and bites of other insects, poison ivy or oak, and other dermatitis presenting as single lesions are common differential diagnoses.⁹

Anaphylactic reactionsrequire immediate attention. Wasps, bees, yellow jackets, and imported fire ants are the most common insect culprits of these reaction types. Reportedly, 50 to 100 deaths occur each year as a result of anaphylaxis from stinging insects. The sensitivity of a child’s immune system to any particular insect venom triggers these types of reactions. Epinephrine by injection is the recommended initial treatment. Because it is important to consider the possibility of biphasic reactions, careful monitoring for several hours is recommended. Patients should be instructed in how to identify the triggers and the signs and symptoms of anaphylaxis, a demonstration by caregiver or self-injection technique, and follow-up of monitoring and care. Most people who get stung, even those with asthma or other lung diseases, do not experience serious reactions. However, those with asthma or lung disease are at risk for a more dangerous reaction.¹⁰

Although tangential to insect bites, any discussion about summer’s finale and back to school activities would be incomplete without the discussion of mites or lice.

Scabiesshould be in the differential diagnosis for insect bites or pruritic eruptions that do not respond to or that worsen with topical steroids. Scabies is a parasitic mite infestation of the skin, manifested by intense pruritus and linear or curved papules or vesicles (1-2 mm wide). Although groupings of burrows and lesions can typically be found in finger or toe webbing, wrists, the sides of hands, fingers, feet, genitalia, and buttocks, isolated lesions can also be noted in scattered, inflamed, hemorrhagic, crusted, or larger nodule formations.

Within 2 to 6 weeks post exposure, the rash and pruritus usually appear. Secondary inflammation or infections can occur as a result of scratching or caustic home remedies. Close contacts are usually symptomatic. Differential diagnoses include insect bites, impetigo, folliculitis, or eczema. Diagnosis may be based upon history and morphology of skin appearance. Mites, eggs, or feces may be identified via scrapings and microscopic examination.

Treatment includes topical pediculicide application to affected areas. Patient education includes instruction on application technique, subsequent bathing, and care of clothes and bedding. Despite clearing of mites, pruritus can continue for weeks or months.

Pediculosis,or lice infestation, is caused by different types of wingless insects named for the preferential area of the body they infect (head, body, or pubic areas). Head lice, commonly found in children, is highly contagious and transmitted with direct contact (hats, brushes, combs, or earphones). Nits, or small oval white eggs cemented on the hair shaft about 1 mm above the scalp, are frequently visible in the occipital area. Mild to intense itching (which is worse at night) is common. Secondary excoriation, infection, and cervical lymphadenopathy can occur. Differential diagnoses include seborrheic dermatitis, impetigo, or insect bites.

Pediculicides applied topically and combing with a special nit comb are the treatments of choice. Lower-strength OTC pediculicides, as well as prescription‑strength rinses and shampoos, are available. Patient education includes careful application and duration of the treatment pediculicides and repeat applications 1 to 2 weeks later to capture any nits or younger lice not eradicated. Treatment of close contacts is controversial. Clothes, brushes, combs, bed linens, and any headgear should be washed in hot water or sealed in plastic bags for 3 days.⁶

Retail clinicians can be instrumental in providing the care and education to help children enjoy all of summer’s escapades and return to school prepared for a thrilling year of learning.

As clinical educator for Healthcare Clinics at Walgreens, Ms. Brautigam enjoys the opportunity to develop program materials and coach best practices for implementation of new and existing services. Karen’s extensive professional experience includes care of patients across the lifespan in hospitals, home services, long-term care, and primary care. Karen graduated from the nurse practitioner program at St. Louis University (adult) and Maryville University (family). She enjoys the challenge of being a member of the adjunct nurse practitioner faculty at St. Louis University, as well as working in research and leadership roles.

References

1. Simons FER. Large local reactions to mosquito bites (skeeter syndrome).UpToDate.www.uptodate.com/contents/large-local-reactions-to-mosquito-bites-skeeter-syndrome.

Accessed June 30, 2015.

2. Insect repellent use and safety. Centers for Disease Control and Prevention website. www.cdc.gov/westnile/faq/repellent.html. Updated March 31, 2015. Accessed July 7, 2015.

3. Castells MC. Insect bites.UpToDate.www.uptodate.com/contents/insect-bites. Accessed June 30, 2015.

4. Habif TP.Skin Disease Diagnosis and Treatment. 3rd ed. Philadelphia, PA: Elsevier; 2011.

5. Insect bites and stings: first aid. Mayo Clinic. www.mayoclinic.org/first-aid/first-aid-insect-bites/ART-20056593?p=1. Published February 20, 2015. Accessed July 7, 2015.

6. Riemann H, High WA. Chigger bites.UpToDate.www.uptodate.com/contents/chigger-bites. Accessed July 3, 2015.

7. Freeman T. Bee, yellow jacket, wasp, and other Hymenoptera stings: reaction types and acute management.UpToDate.www.uptodate.com/contents/bee-yellow-jacket-wasp-and-other-hymenoptera-stings-reaction-types-and-acute-management. Accessed July 3, 2015.

8. Elston DM, Kells S. Bedbugs: beyond the basics.UpToDate.www.uptodate.com/contents/bedbugs-beyond-the-basics. Accessed July 3, 2015.

9. Vetter RS, Swanson DL. Approach to the patient with a suspected spider bite: an overview.UpToDate.www.uptodate.com/contents/approach-to-the-patient-with-a-suspected-spider-bite-an-overview. Accessed July 3, 2015.

10. Wings and stings. Healthychildren.org website. www.healthychildren.org/English/health-issues/conditions/from-insects-animals/Pages/Wings-and-Stings.aspx. Updated May 5, 2015. Accessed July 7, 2015.