DD- Common Infections and Infestations of the Skin Flashcards
Acquired- breaks in skin/mucosa
20 million+ (US)
–Person-to-person contact
–Fomites
Human Papillomavirus
Human Papillomavirus
Virology
Non-enveloped double-stranded DNA
virus
Verruca Vulgaris
“Warts”
fingers/lips
From HPV
Vulgaris means
Common type
Verruca Plantaris
Wart on sole of the foot
From HPV
Verruca Plana
flat warts
From HPV
Diagnosis of warts
Clinical
• Biopsy
• In-situ hybridization
General ways to treat warts
Rev up immune system
Destroy the skin that has the virus
Pulse dye laser
Vascular Laser
Decreases blood flow to local area
Herpes Simplex Virus
Epidemiology
HSV-1- >90% prevalence by 2
Herpesvirus group virus locations
– HSV-1- lips
– HSV-2- genitalia
Varicella-Zoster Infection
> 90% of adults have VZV antibodies
Primarily spread by respiratory route
Highly communicable
Causes Chicken Pox
Acyclovir traets
herpes
front line rx
short half life
Chickenpox
Incubation period- about 14 days
– Fever
– Thin-walled vesicles
-New crops every 3-5 days
– Lesions in multiple stages of development
Herpes Zoster is caused by?
VZV!!!!!
-“Shingles”
Herpes only means grouped vessicles
Impetigo Epidemiology
superficial bacterial infection of children • Acquired by person-to-person contact • Predisposing factors- high humidity, cutaneous carriage, poor hygiene * Strep or Staph
Streptococcal Non-Bullous Impetigo
Impetigo Contagiosa
- “honey-colored” yellow crust
- affects face
- associated with acute post-streptococcal
- glomerulonephritis
Staphylococcal Non-Bullous Impetigo
Frequently a secondary lesion of
superficial injury or dermatitis
yellow to ambercolored crust
Cellulitis
Epidemiology
Increased susceptibility: –Very young – Elderly – Immunocompromised – Intravenous drug users – Patients with chronic ulcers Post-surgical complication
Cellulitis may show
lymph streaking
needs rx
Erysipelas
Cellulitis on the face
Can you culture syphilis?
nope
Primary syphilis
Incubation- 10-90 days
– Inversely proportional to inoculum’s size
*Secondary syphilis
Usually seen in clinic
Begins 4-10 weeks after onset of chancre
Diffuse body rash and of palm* and sole*
ORGANISM IS IN THE SKIN
Chancre
Non-tender ulcer
• Indurated
• Heals- 3-6 weeks
• Lymphadenopathy
Moth-eaten Alopecia
patchy alopecia
2a syphilis
Dermatophytes
Fungus- They eat keratin (hair, skin, nails)
Tinea Capitis
fungal infection on scalp
May look like a round worm
NO WORM
Kerion
area of inflammation induced by the fungus
- purulent
- ABs will not work!
Tinea faciei
fungus on face
scaly border
Tinea Barbae
Fungus in the beard area (may be caused by shaving)
Tinea Corporis
“ring worm”
central clearing
raised edge
NOT A WORM
Majocchi’s Granuloma
Hair follicles infected by fungus
Interdigital tinea pedis
Fungus on the foot
Tinea Pedis Hyperkeratotic
*MOST COMMON
Looks like dry feet
Tinea Manum
Fungus on the hand
Just one hand
Comes from the foot usually
Two-Feet-One-Hand Syndrome
Tinea Manum + Tinea Pedis Hyperkeratotic
Onychomycosis- Subungual
Nail fungus
Onychomycosis means?
lifting of nail bed
Positive KOH
Highlights the fungus
Tinea Pedis- Topical Treatment with ______
Naftifine
Affects mucous membranes and skin • Increased prevalence – Diabetes mellitus – Occlusion –Corticosteroid use –Broad-spectrum antibiotics • Found as normal flora *Preferred food source- glucose or serum
Candidiasis
Can cause all kinds of trouble
Candidiasis are usually ______ unlike dermatophyte
inflamation
Thrush
Candidiasis causing infection of the mouth
More common in humid and warm
climates
Confined to post-pubertal patients
Primarily truncal “V SHAPED”
asymptomatic, tancolored, subtly scaly macule or patch
Tinea Versicolor
• Clinical variants
– Hypopigmented variant
– Folliculitis
Scabies
A contagious, intensely itchy skin condition caused by a tiny, burrowing mite
Person to person contact
Inter-digit/ Genital common
obligate ectoparasite of humans that causes pediculosis capitis.
Insects spending their entire life on the human scalp and feeding exclusively on human blood.
Head lice
*Very common
Body lice is common?
in bad hygiene
Creb Lice common in
adult sexually active males
Head lice lay their eggs?
an inch away from the scalp on the hair
Body lice live on the?
Clothing
Feed on the skin