Dandruff, Lice, and Pinworms

dandruff

-chronic, relapsing, mild inflammatory disorder of the scalp

-mildest and most common form of scalp seborrheic dermatitis

adolescents and adults (usually appears with puberty onset and no sex preference)

Dandruff most commonly presents in who?

-hormones (puberty)

-weather (less severe in the warmer months)

-stress

What are the exacerbating factors for dandruff?

patho of dandruff

-caused by accelerated epidermal cell turnover due to malassezia (yeast like fungi) colonization of the scalp

-large, white, scaly shedding from superficial cracking of stratum corneum

clinical presentation of dandruff

-characterized by diffuse white, scaly flakes without underlying erythema

-presents around the crown of the head

-can be asymptomatic or with mild pruritus

-often a source of embarrassment for pts

-reduce epidermal turnover rate by reducing Malassezia species in the scalp

-minimize cosmetic embarrassment

-minimize discomfort associated with inflammation and pruritus

What are the goals of tx with dandruff?

pyrithione zinc or selecium sulfide

What is the first line tx for dandruff?

ketoconazole

What is the alternative tx for ketoconazole?

medical referral

If the pt experiences no symptom resolution at least 2 weeks after use of OTC meds for dandruff they should get a _________

scalp scrubbers

What can be helpful in long hair with dandruff?

switch to a diff product

If one product's efficacy begins to fade you should:

- < 2 yrs of age

-worsening symptoms or no improvement after 2 weeks of proper use of OTC meds

What are the exclusions for self tx of dandruff?

Cytostatic agents

-pyrithione zinc

-selenium sulfide

-coal tar

antifungal agent

ketoconazole

keratolytic agents

-salicylic acids

-sulfur

Pyrithione Zinc 1-2%

• Reduces yeast count in the scalp and skin

• Available as shampoo and soap

• Ex. DHS Zinc, Head & Shoulders, Zincon

• Well tolerated

• Avoid contact with eyes

Selenium Sulfide 1%

• Reduces yeast count in the scalp and skin

• Available as shampoo

• Ex. Selsun Blue

• More effective with prolonged contact time

• Rinse thoroughly. Discoloration can occur, especially with light or dyed hair

• Residual odor or oily scalp with frequent use

• Avoid contact with eyes

Coal Tar 0.5-5%

• Cross-links with DNA, arresting excessive skin cell proliferation

• Available as creams, ointments, bath oils, shampoos, etc.

• Ex. DHS Tar, Pentrax, Neutrogena T/Gel

• Adverse effects of folliculitis, skin and hair staining, photosensitivity, and irritant contact dermatitis

• Apply overnight and bathe in the morning - use linens and clothes that are okay to stain

• Avoid sun exposure for 24 hours after application

Ketoconazole 1%

-Active against most fungi, but indicated specifically for Malassezia

-Inhibits fungi cell wall lipid creation ->Alters cell membrane ->

leaky

• Has local antiandrogen activity

-Available as shampoo OTC or RX

-Adverse effects: hair loss, skin irritation, abnormal hair texture, and dry skin

-Use twice a week for 4 weeks, with at least 3 days between each

treatment

-Once controlled, the shampoo can be applied once weekly

-Avoid contact with eyes

Salicylic acid 1.8-3%

-Decreases skin pH, hydrating keratin and facilitating its

loosening and removal

-Available as shampoo

-Ex. Denorex Extra Strength, Sebulex, MG217 Shampoo and

Conditioner

-application over extensive areas should be avoided

Sulfur 2-5%

-Increases sloughing of cells

-Often combined with salicylic acid as shampoo

-Ex. Sebulex

-not associated with significant AEs

keratolytic agents

• Prolonged use (>4 weeks) usually is necessary to obtain a

therapeutic response

• Concentration-dependent irritant effect, particularly on mucous

membranes and the conjunctiva of the eye

general tx approach to tx of dandruff

-Shampoo with nonmedicated product before medicated shampoo

-After rinsing, apply medicated shampoo

-Leave on the scalp for up to 5 minutes

-Perform this regimen daily, if needed, then 2-3 times weekly with relief of symptoms

-Coarse or curly hair - may benefit from shampooing once weekly

• head lice (Pediculus humanus capitis)

• body lice (Pediculus humanus corporis)

• Pubic lice (Phthirus pubis)

What are the 3 types of lice?

life cycle of lice

-Day 0: louse egg is laid on the hair shaft

-Day 6-7: young louse hatches

-Day 8-9: fist mold 2 days after hatching

-Day 11-12: second molt 5 days after hatching

-Day 16-17: third molt 10 days after hatching

-Day 17-19: mole and slightly larger female begin to reproduce

-Day 19-32: female lays 1-2 eggs after mating. Female continues to lay 4-8 eggs a day for 16 days

-Day 33-35: the louse dies

head lice

• A common condition caused by infestation of the hair and the scalp

• children are affected more frequently

• Primary mode of transmission is direct contact with head of infected persons

• Bite causes a wheal to develop immediately, with papule

development within 24 hours

• Adult lice are difficult to detect

• Nits and nit casings can be seen at the base of the hair shaft

• Presence of black powdery specks can also be evidence of infestation

• Major symptom - itching

body lice

-live, hide, and lay eggs in clothing, especially underclothes

-typically linked to suboptimal hygiene

pubic lice

-Transmitted through high-risk sexual contact, toilet seats, shared undergarments

-Can also be found in armpits, eyelashes, mustaches, beards, eyebrows

-eliminate the lice infestation in the pt (killing adult and nymph lice and removing nits)

-prevent future infestations

What are the goals of lice tx?

Pediculicides

Use of nonprescription pediculicide agents

Lice/Nit combs

hair combing with lice or nit comb for removal

cleaning

home vacuuming and personal item cleaning

exclusions for self-tx for lice

-Hypersensitivity to chrysanthemums, ragweed, or pediculicide

ingredients

-Secondary skin infection

-Pyrethrins: Age <2 years

-Permethrins: Age <2 months

-eyelid or eyebrow involvement

-Pregnancy or breastfeeding

-Presence of active tumors

-Regional pediculicide resistance

non-pharm therapy for lice

-Clothing, bedding, stuffed animals/toys, pillows

• Wash in hot water and dry on high heat

• Quarantine in plastic bags for 2 weeks

-Hairbrushes, combs

• Wash in hot water over a sink NOT in shower

• Do not share hygiene items

-Carpet, rugs, and furniture

• Vacuum frequently

-Treat household and other close contacts

-Visual inspection and physical removal

OTC tx for lice

-synergized pyrethrins

-permethrins

-ivermectin

Synergized Pyrethrins

-Pyrethrins + piperonyl butoxide

-Indicated for head lice and pubic lice treatment

-Blocks insect's nerve impulse transmission → paralysis → death

-Addition of piperonyl butoxide inhibits pyrethrin breakdown to enhance insecticidal effect

-Available formulations:

• Pyrethrins 0.17-0.33% with 2-4% piperonyl butoxide

• Topical application: foam, gel, shampoo, solution

-Adverse effects: cutaneous irritation, erythema, itching, and swelling

• Apply for 10 minutes, then rinse or shampoo

• Comb with lice comb

• Repeat in 7-10 days

• Do not apply more than twice in 24 hours

How do you use synergized pyrethrins?

Synergized Pyrethrins: Products

• A-200 Lice Killing Shampoo

• RID Lice Killing Shampoo

• Pronto Lice Killing Shampoo

precautions with synergized pyrethrins

• Contact with eyes and mucous membranes should be avoided

• Individuals allergic to pyrethrins or chrysanthemums

should not use this agent; ragweed-sensitive individuals risk cross-sensitivity

• Pyrethrins should not be used in children < 2 years

Permethrin

-Synthetic pyrethroid

-Indicated for head lice

-Disrupts sodium channel of nerve cell membrane in lice → paralysis → death

-Available formulations:

• Permethrin 1% cream rinse (Nix Lice Killing Cream Rinse)

• Adverse effects: transient pruritus, burning, stinging, and irritation of the scalp

• Apply for 10 minutes, then rinse or shampoo

• Comb with lice comb

• Retreatment in 7-10 days is not required due to residual effects lasting up to 10 days

• Do not apply more than twice in 24 hours

How do you use Permethrin?

• Ragweed sensitivity: difficulty breathing or an asthmatic episode

• Avoid contact with eyes and mucous membranes

• Do NOT use permethrin in infants

< 2 months of age

What are the precautions with Permethrin?

Ivermectin 0.5% Lotion

• Increases chloride ion permeability of muscle cells, resulting in hyperpolarization, paralysis, and death of the lice

• Originally only available with a valid prescription, now available OTC

• Avoid in hypersensitivity and in <6 months

• single application

• Adverse effects: scalp and eye irritation

Treat:

-Ensure scalp and hair is dry before applying

-Apply directly to dry hair and scalp

▪ Completely cover scalp and hair closest to scalp first

-Rub product thoroughly throughout hair/scalp

Wait and rinse

-Allow product to sit for 10 minutes before rinsing

-Wait 24 hours before applying shampoo

After treatment

-Wash hands

-Nit combing isn't necessary

-Discard tube after use

What are the instructions for Ivermectin 0.5% lotion?

alternative therapies for lice

-Lice enzyme shampoos

-Tea tree oil (10%) + lavender oil (1%) weekly x 3 weeks

• Use with caution due to common allergies

-Petroleum jelly or mayonnaise

-MagiComb and RobiComb

-Lice Shield®

-Dimethicone 100% gel

Nuvo Method

-emerging therapy

-dry on, suffocation-baed pediculicide (DSP) lotions

• Cetaphil cleanser applied to hair

• Comb out excess

• Use a blow dryer to form "shrink wrap"

• Ultimately suffocates the louse

Ivermectin Oral Formulation

• Use if head lice is resistant to all topical FDA-approved

treatments

• Treatment with 2 single oral doses of 200 mcg/kg, spaced 7 to 10 days apart

• Use with caution in children weighing <15 kg

• Likely safe during pregnancy

Malathion 0.5% Lotion

• High kill rates (ovicidal activity) after 1 application but still applied twice within 7-9 days

• High alcohol content = highly flammable

• Let hair dry naturally - do not use blow dryer

• Safety & efficacy not established in < 6 years, contraindicated

< 24 months

Spinosad 0.9% Suspension

• Broad insecticidal activity; disrupts neuronal activity in lice and developing larvae

• Superior to permethrin (84% vs 43%)

• Adverse effects: erythema, ocular erythema

• Contraindicated < 6 months

elementary school-age children

Who does head lice occur most commonly in?

topical pyrethrins and permethrin

What are the OTC drugs of choice for lice?

decreased

Efficacy with pyethrins has __________ due to resistance. Treatment should be repeated on day 9.

2 weeks

When should follow up occur during tx of lice?

seek medical attention

If there is resistance to treatment or if signs persist after recommended application, patient should:

Pinworm (Enterobiasis vermicularis) Etiology

• Person to person via anus to mouth when using contaminated fingers to handle and eat

• Wash hands before eating!!!!!

Pinworms

Appearance

• Small (length of a staple), white, threadlike, pin-shaped pointed tail

Signs and symptoms

• perianal itch

• Disturbed sleep

• Irritability

Diagnosis

• Scotch tape test

eradication from patient and household

What are the tx goal with Pinworm tx?

general non-pharm tx approach to pinworms

• Wash sheets, pajamas, towel, underwear, etc

• Open blinds/curtains

• Morning showers

• Disinfect toilet seats

• Vacuum

• Close-fitting clothes when sleep

• Wash hands

• Nail - wash under and keep trim

pharmacological tx for pinworms

Pyrantel pamoate

pyrantel pamoate

-Dose based on weight ( 11 mg/kg; max 1 g)

• Refer <2 yo or <25 lb)

-Treat entire family today

-Consult physician: repeat in 2 weeks if symptoms do not resolve

-Contraindicated:

• Pregnancy

• Liver disease