Dermatology MDT's Flashcards
Folliculitis Most commonly infectious etiology
Most frequently due to S. aureus (+/- MRSA)
Streptococcus species, Pseudomonas (contaminated H20 contamination) Use of hot tubs or saunas
Non-Infectious
Mechanical Folliculitis (Skinny Jeans Syndrome)
Pseudo-folliculitis barbae (PFB)
Pseudomonas folliculitis appears as a
widespread rash, mainly on the trunk and limbs
The clinical hallmark of folliculitis
hair emanating from the center of the pustule.
Initial care for folliculitis
Mupirocin ointment applied TID for 10 days
Cephalexin: 250-500 mg PO QID (7-10 days)
Dicloxacillin: 250-500 mg PO QID (7-10 days
MRSA:
(a) Bactrim DS: 1-2 tablets BID PO (5-10 days)
(b) Clindamycin: 300 mg PO TID (10 to 14 days)
(c) Doxycycline: 50-100 mg PO BID (5-10 days)
Treatment of PFB
Treatment Approach 1 - Medical Treatment with Grooming Modifications (for Mild to Moderate PFB)
Topical retinoid or eflornithine 13.9% (if available) and a temporary waiver of
facial hair standards for up to 60 days.
Treatment Approach 2 - Laser Hair Reduction with grooming modifications (moderate to severe PFB)
Primary impetigo vs Secondary impetigo
Primary= invasion of normal skin
Secondary= Invasion at sites of minor trauma
A contagious, superficial, intraepidermal infection occurring prominently on exposed areas of the face and extremities
Impetigo
Bacteria that cause impetigo
Staphylococcus aureus alone or combined with group A β-hemolytic streptococci
A deeper, ulcerated impetigo infection often with lymphadenitis
Ecthyma
Most common form of impetigo. Formation of vesiculopustules
that rupture, leading to crusting with a characteristic golden appearance
Nonbullous impetigo:
Staphylococcal impetigo that progresses from small to large flaccid bullae (newborns/young children) caused by
epidermolysis toxin release; ruptured bullae leaving brown crust
Bullous impetigo
Impetigo Risk Factors
Warm, humid environment
Minor trauma, insect bites, breaches in skin
Poor hygiene, poverty, crowding, epidemics, wartime
Familial spread
Complication of pediculosis, scabies, chickenpox, eczema/atopic dermatitis
Complications of impetigo
(1) Ecthyma
(2) Cellulitis
Unilateral lower-extremity involvement is typical and systemic symptoms are
usually absent
Most common portal of entry for lower leg cellulitis is toe web intertrigo with fissuring,
2/2 interdigital tinea pedis.
Cellulitis
Useful diagnostic testing for cellulitis
Plain radiographs, CT, or MRI are useful if osteomyelitis, fracture, necrotizing fasciitis,
retained foreign body, or underlying abscess is suspected.
US to r/o Deep Vein Thrombosis (DVT)
initial Cellulitis Treatment
Demarcate area w/a sharpie to measure progress once you start treatment.
Immobilize and elevate involved limb to reduce swelling.
Sterile saline dressings or cool aluminum acetate compresses for pain relief
Acetaminophen +/- NSAIDs for pain relief
Tetanus immunization if needed, particularly if there is an open wound.
Medication for cellulitis
Non-purulent cellulitis
1) Cephalexin 500 mg
2) Dicloxacillin 500 mg
Purulent cellulitis
1) Clindamycin 450mg
2) Trimethoprim-sulfamethoxazole
3) Doxycycline 100 mg
Human/animal Bites
1) Amoxicillin + clavulanic acid (Augmentin)
Necrotizing Fasciitis Treatment
Prompt and wide surgical debridement is the cornerstone of treatment.
Broad-spectrum antibiotics should be administered once diagnosis of NSTI is
suspected.
A well-circumscribed, painful, suppurative inflammatory nodule at
any site that contains hair follicles
Furuncle (AKA boil)
A collection of pus within the dermis and deeper skin tissues.
Skin abscess
A coalescence of several inflamed follicles into a single inflammatory mass with purulent drainage from multiple follicles
Carbuncle
Typically presents with systemic symptoms and fever
What is the mainstay of treatment for an abscess, furuncle, or
carbuncle.
Incision and Drainage
the most common benign cutaneous cysts.
Epidermal cysts
The most common benign mesenchymal neoplasm in adults and are composed of
mature white adipocytes.
Lipoma
Most common cause of paronychia
Most commonly caused by Staphylococcus aureus, Streptococcus pyogenes infection in
the periungual tissues
Paronychia Treatment
Early treatment with warm compresses or soaks
Antibiotic therapy if warranted that includes coverage for Staph and strep.
Bactrim/Septra DS in areas where MRSA is common and based on results of sensitivity
testing.
Fluctuant or visible pus should be drained using scalpel blade inserted between the nail
and nail fold
Skin incision is unnecessary.
Felon Treatment
Prompt incision, with division of the fibrous septa to ensure adequate drainage by dermatologist
IDC should treat with antibiotics.
(a) MSSA- Systemic antibiotics - Dicloxacillin or Keflex are indicated.
(b) If MRSA suspected, trimethoprim/sulfamethoxazole, clindamycin, or doxycycline,
should be used
Candidiasis and fungal treatment
First Line (Topical)
1) Clotrimazole Vaginal Cream (Gyne-Lotrimin)
2) Miconazole Nitrate Vaginal Cream (Monistat)
Second Line (Oral)
1) Fluconazole (Diflucan)
Tinea infections
Pedis = foot
capitis = head
Curis= balls
Corpis = body
What causes tinea infections
Dermatophytes can subsist on protein, namely keratin and can cause disease in keratin rich structures such as skin, nails, and hair.
Infections result from contact with infected persons/animals
Tinea versicolor caused by
Pityrosporum orbiculare, which is part of the normal skin flora
likes sebum
excess heat and humidity predispose to infection
Not linked to poor hygiene
Presentation of tinea versicolor
Velvety tan, pink or white macules that do not tan.
Treatment of tinea versicolor
Selenium Sulfide 2.5% applied from neck to waist wash off after 5-15 minutes, repeat daily x 7 days. Repeat weekly x 1 month, then monthly for maintenance.
Ketoconazole 2% shampoo chest and back, wash off after 5 minutes. Repeat
weekly.
Oral treatment is used for patients with extensive disease and those who do not
respond to topical treatment
Ketoconazole 400 mg in a single dose with exercise to point of sweating
after ingestion. Single dose is not always effective.
Fluconazole 300 mg (2 capsules weekly x 2 weeks) has similar efficacy.
Treatment onychomycosis
Confirmation of infection is required prior to treatment due to potential for liver
toxicity of treatment with oral antifungals
Potassium hydroxide (KOH) preparation (confirms presence of infection) and
fungal culture (determines the type/species of the actual infecting organism).
A contagious parasitic infection of the skin caused by the mite Sarcoptes scabiei, var. homini
Scabies
Scabies rash appears how long after exposure
2-6 weeks