(13) Burns, Wounds, Insect Bites, Stings, and Pediculus

PART 1 — BURNS & WOUNDS

1. Wound Healing

2. Wound & Burn Types

3. Treatment

   1. Process

   2. Products

      • Wound Products

      • First-Aid Antibiotics

      • Other Topicals

Wound Healing

Phase	Timing	Function
Inflammatory	First 3–4 days	Clotting + remove bacteria/debris
Proliferative	Day 3–3 weeks	New tissue + blood vessels
Maturation	Week 3 onward; peaks ~day 60	Stronger collagen replaces weak collagen

Wound Healing

Factors delaying healing:

• Poor blood flow, dry wound, infection.

• Older age, stress, poor nutrition, obesity, smoking.

• Diabetes, cancer

Wound Healing

Three drugs/classes that delay heaing

• Corticosteroids → Suppress immune system.

• Chemotherapy → Suppresses immune function.

• Anticoagulants/antiplatelets → Interfere with clotting.

Wound & Burn Types

Type	Recognize
Abrasion	Scrape/friction injury
Laceration	Cut or puncture
Thermal burn	flames, heat, hot liquid
Sunburn	UV exposure
Chemical burn	🚨 Refer
Electrical burn	🚨 Refer
Inhalation burn	🚨 Refer

Wound & Burn Types

Burn Depth

Type	Skin affected	Action
Superficial	Epidermis; red, no blisters	Self-care
Superficial partial	Epidermis + part of dermis; blisters	Self-care if otherwise eligible
Deep partial	Deep dermis	🚨 Refer
Full thickness	Into subcutaneous tissue	🚨 Refer
Subdermal	Muscle/tendon/bone	🚨 Refer

Treatment

Process

1. Irrigate with tap water.

2. Apply skin protectant (petrolatum).

3. Cover with appropriate dressing.

4. NSAID or acetaminophen for pain.

5. Check tetanus vaccination status.

• Keep wounds MOIST, not dry.

• Follow-up:

  • Burns → 24–48 hours.

  • Other wounds → 7 days.

Treatment

Wound Products

Product	Main purpose
Petrolatum	Prevents drying
Gauze	Covers wound; can stick
Adhesive bandage	Superficial wounds
Hydrocolloid	Forms gel with wound moisture
Transparent film	Waterproof, flexible; joints
Silicone gel/sheets	⭐ Gold standard for scars

Pain medications:

• NSAIDs → Pain + inflammation.

• Acetaminophen → Pain, NOT inflammation.

Treatment

First-Aid Antibiotics

Drug	Mechanism	Important
Bacitracin	Cell wall inhibition	Mainly gram-positive
Neomycin	30S protein synthesis inhibition	⚠ Hypersensitivity, contact allergy.
Polymyxin B	Alters membrane permeability	Mainly gram-negative

• Apply 1–3 times/day.

• Clean wounds may not need antibiotics.

Bitchy NP

Treatment

Other Topicals

ategory	Know
Antiseptics	hydrogen peroxide, povidone-iodine not routinely needed. can irritate wound generally use on intact skin
Anesthetics	Temporary pain relief; not routinely needed. Benzocaine (Hypersensitivity risk) , lidocaine, pramoxine, tetracaine Anesthetic duration - 15–45 minutes

Dosage forms:

• Ointment → Intact skin.

• Cream → Broken skin.

• Lotion → Large areas.

• Spray → Avoid touching area; alcohol sprays may irritate.

PART 2 — INSECT BITES & STINGS

1. Insect Recognition

2. Insect Repellents

3. Treatment

   1. OTC Insect Bite Treatment

   2. Bee vs. Tick Removal

Insect Recognition

Insect	Associated disease / clue
Mosquito	Dengue, Malaria, West Nile, Zika
Tick	Lyme, Rocky Mountain spotted fever
Flea	Bites legs/ankles
Bed bug	Bites during sleep, no disease transmission
Black widow	Neurotoxin → Spreading pain
Brown recluse	Necrosis → Tissue death

✅ Special associations:

• Lyme → Bull's-eye rash.

• Zika → Microcephaly.

• Rocky Mountain spotted fever → Fever, headache, possible rash

Insect Repellents

Repellent	Memorize
DEET	⭐ First-line Age >2 months. Concentration ↑ = duration ↑ up to 50%. Children: 10–30% (50% provides no additional benefit.)
Picaridin	Second-line ≥6 months.
IR3535	Alternative
Oil of lemon eucalyptus	Avoid under age 3
Citronella/catnip	Not recommended in lecture

Counseling

• SUN: Sunscreen before repellent.

• SKIN: Avoid eyes, mouth, wounds, children's hands.

• WASH: Wash off when indoors.

🚨 Repellents do NOT prevent stinging insects.

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OTC Insect Bite Treatment

Goal	Drug	Remember
Protect	Calamine, zinc oxide	Suitable for infants
Itch	Diphenhydramine topical (Antihistamine)
Inflammation	Hydrocortisone 0.5–1%	2–4 times/day Avoid eyes/eyelids prolonged or large-area use increases absorption risk.
Numb	Benzocaine, lidocaine, pramoxine	Allergy possible
Counterirritant	Camphor, menthol	Camphor toxic if swallowed

Non-drug: Cold pack 10 minutes; 10-minute break.

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Bee vs. Tick Removal

Bee stinger	Tick
Remove immediately	Remove intact
Avoid squeezing venom sac	Fine-tipped tweezers
Cold pack	No oils, matches, alcohol
Lecture: Venom release 2–3 min	Watch for infection/systemic symptoms

PART 3 — Pediculosis (Head Lice)

1. Lice Basics

2. Treatment

   1. OTC Lice Treatments

   2. Lice Treatment Algorithm

   3. Prescription Treatments

3. Lice Counseling

Lice Basics

Category	What to memorize
SPREAD	Head-to-head contact does NOT transmit disease
SYMPTOMS	Itching from sensitivity to lice saliva
NITS (EGGS)	Attached near scalp hatch in 8–9 days
SURVIVAL	Lice survive less than 24 hours off scalp nits >1 cm from scalp generally not viable

🚨 EXAM ALERT: Only initiate lice treatment when live lice are observed.

SSNS - Social Security Number Stolen

OTC Lice Treatments

• NIR - Now It Ranvir!

OTC Lice Treatments

NIX

• Na Channel disruption.

• Nits - NOT killed

• Newly hatched lice - leaves residue

• nonconditioning shampoo first.

3N + Non Conditioning Shampoo

OTC Lice Treatments

IVERMECTIN

• Hyperpolarization → Paralysis.

• Useful with pyrethroid resistance/failure.

• Rinse with water only; Wait 24 hours to shampoo.

OTC Lice Treatments

RID

• Neurotoxic to lice.

• Nits - NOT killed

• Newly hatched lice - leaves NO residue

(3N)

Lice Treatment Algorithm

Prescription Treatments

Drug	Key fact
Malathion	≥6 years; flammable
Spinosad	≥6 months; kills nits
Benzyl alcohol	No longer marketed

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Lice Counseling

• COMB:

  • Remove nits near scalp

  • wet hair makes combing easier.

• CLEAN:

  • Wash clothes/bedding at >130°F, dry high heat

  • vacuum

  • bag nonwashables for 2 weeks.

• CHECK:

  • Household members for lice

🚨 Never recommend insecticide household sprays.

3C

Burns and Wounds

Exclusion Criteria

Category	What to remember
1. SIZE	Cut >½ inch; wound >3 inches; burn ≥10% adult or ≥5% child BSA
2. SEVERITY	bleeding >10 mi Deep burn, circumferential burn Chemical, electrical, inhalation burns
3. LOCATION	Face, hands, feet, major joints, genitals, perineum
4. CAUSE	animal/human bites; suspected abuse
5. Time and HEALING PROBLEMS	worsening/not healing in 7 days Infection, diabetes, foreign body, chronic wound

Sunburn referral:

Group	Refer if
SKIN	Large blisters, severe swelling, infection
BODY	Fever, extreme pain
BRAIN	Headache, dizziness, confusion, vision changes

Insect Bite/Sting

Exclusion Criteria

Group	Refer if
Age	Under 2 years
Allergy	Systemic symptoms; concerning allergy history
Infection	Secondary skin infection; tick bite with systemic illness
Danger	Concerning spider bite; suspected scabies
Time	Not resolved after 7 days

Sting-specific red flags:

• Hives or swelling away from sting.

• Dizziness/weakness.

• Nausea/vomiting.

• Difficulty breathing.

🚨 Anaphylaxis = Emergency.

Lice

Exclusion Criteria

• AGE: Below approved age.

• ALLERGY: Chrysanthemum/pyrethrin sensitivity, ingredient allergy, secondary scalp infection.

• LOCATION: Eyelash/eyebrow lice.

• PATIENT: Pregnancy/breastfeeding, active tumors, resistance concerns.