Podcast: Play in new window | Download
Spider Bites
- Brown Recluse (necrotizing venome)
- Black Widow (neurotoxic venome
Brown Recluse spiders
- Found in the mid-southeastern states
- Here is a map of where they are found and a good article if you’re interested in learning more.
- The venom contains an enzyme that causes cell membranes to breakdown leading to significant tissue damage.
Clinical Presentation
- The initial bite is usually painless but will become painful over about an hour
- The bit may also be pruritic
- The lesion goes through a phase of erythema, blanching, and ecchymosis. It is therefore sometimes referred to as red white and blue
- The most severe cases have to do with either the venom traveling in the bloodstream or a severe allergic reaction.
Treatment
- There is no particular treatment for the bite.
- Wash it, keep it clean
- Debridement may be necessary
- Antibiotics may be necessary
Black Widow
- There are many types of widows spiders, and most of them are not dangerous to humans.
Clinical Presentation
- The bite is usually painful and can be dull and numbing. Pain is out of proportion to the bite.
- Severe symptoms are primarily pain and muscle cramping.
- HTN and tachycardia may also be seen.
- Headache, nausea, and vomiting are more severe symptoms
Treatment
- Monitoring and cleaning the site of the wound
- Opioids and benzodiazepines for pain
- Anti-venom is available for severe cases.
Derm Parasites
Lice
- Bloodsucking insects
- Transmitted through close contact
- Three types of lice
- Head lice (most commonly found in girls age 5–11)
- Body lice
- Maybe vector for other diseases like typhus
- Live on bedding or in clothes. Move to the body to feed
- Pubic lice
Clinical Presentation
- Head lice
- Itching of the scalp
- Body lice
- Severe body itching
- Pubic lice
- Itching of the pubic area
Labs, Studies and Physical Exam Findings
- Head lice
- Small nits at the base of the hair follicles (White oval shaped eggs)
- Isolate the organism using a fine tooth comb
- Excoritians may be found
- Body lice
- Linear excoriations
- Small red bites
- Pubic lice
- Isolate the organism
Treatment
- For pubic or head lice the primary treatment is Permethrin 1% applied to the affected area after shampooing and rinsed out ten minutes later.
- Body lice
- Patient’s clothes & bedding should be thoroughly cleaned at high temperatures
- Topical treatment not necessary because lice do not live on the body.
- Sexual partner should be treated as well
Scabies
- Mites that cause a severe itching reaction
- Easily transmitted from person to person
Clinical Presentation
- Severe itching
- Most common locations include
- Webs spaces of the fingers
- Wrists
- Waistband
- Genitals
Labs, Studies and Physical Exam Findings
- Track like raised burrows. These are linear and pruritic
- Microscopic examinations of skin/burrow scrapings under oil immersion
Treatment
- Permethrin, 5% cream, is the most common treatment.
- Apply one time to all skin surfaces. Wash off in the morning
- All family members and sexual partner should be treated regardless of symptoms
- It may take up to two weeks for symptoms to resolve because there is an allergic reaction to the eggs
- Antihistamines and steroids may be helpful for treating symptoms
- Thoroughly wash all household items including
- Clothes
- Bedding
- Towels
Fungal Infections
Candida Diaper dermatitis
- A secondary infection following several days of severe diaper rash
- Recurrent infections may be a sign of DM 1
Clinical Presentation
- Red plaques with satellite lesions
- Primarily involve the skin folds
Labs & Studies
- Diagnosis is typically clinical
- KOH prep with pseudohyphae or culture will confirm the diagnosis
Treatment
- Antifungal ointment
- Steroid cream is not recommended in infants.
Intertriginous Dermatitis
- A common inflammatory condition of skin folds characterized by moist erythema, malodor, weeping, pruritus, and tenderness
- Caused by moister in deep skin folds
- Risk factors include
- Obesity
- Poor hygiene
- Immunodiffeicney
Clinical Presentation
- Beefy red patches
- Most common locations
- Axilla
- Inframammary folds
- Groin
- Beneath a large panus
- Satellite lesions are ann indication of Candida
Labs & Studies
- Diagnosis is typically clinical
- KOH prep with pseudohyphae or culture will confirm the diagnosis
Treatment
- Cleansing and drying of the affected area
- Weight loss
- Antifungal cream
- Ketocnoazole
- Clotrimizole
Dermatophyte Infections (Ringworm)
- A fungal infection affecting the skin, hair and or nails
- Infections are described by their location
- Tinea pedis foot – athletes foot
- Tinea cruris groin – jock itch
- Tinea corporis – trunk, legs, arms or neck
- Tinea barbae – beard area
- Tinea unguium – nails
- Tinea manuum – hand
- Tinea faciales – face
- Tinea capitis – head
Clinical Presentation
- Red raised ring with a central clearing and distinct borders
- Itching, stinging and burning
- If located between digits maceration is common
- Broken hair shafts may be present with a scalp infection
Labs and Studies
- Often a clinical diagnosis
- KOH prep can be done to confirm the diagnosis
- A woods light may be helpful
- Culture may be useful
Treatment
- Mostly topical creams, ointments, lotions, sprays, and powders
- Nail infections may be more challenging to treat.
- No steroids. They will initially cover up the redness and make things worse in the long run
- Keep the area clean and dry. For example, change socks often for athletes foot
(Pityriasis Versicolor) Tinea versicolor
- A chronic fungal infection
Clinical Presentation
- Rash mainly on the upper trunk and proximal extremities
- Tan or pink macules that do not tan
- Mild pruritus
- Clear borders
- Symptoms are much worse in hot or humid climates
Labs and Studies
- KOH prep reveals round yeasts with filaments giving a spaghetti and meatball appearance
Treatment
There is a high recurrence rate even with treatment
- Topical
- Selenium Sulfide lotion 2.5% x 7 days
- Repeat for maintenance
- Ketoconazole shampoo used weekly
- Systemic
- Ketoconazole 200 mg daily x 7 days (delivered through sweat to the skin. Do not shower for 8 hours after taking)
- Fluconazole 300 mg two doses 14 days apart