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Dermatology
“Doc, I Have This Rash…”
Joseph S. Baler M.D.
September 7, 2013
Guttate Psoriasis
• Small pink papules
with scale.
• Scalp, face, trunk,
and ext.
Guttate Psoriasis
• 2-3 wks post group A
strep.
• Personal or family h/o
psoriasis.
• May be initial psoriatic
event.
• Post sunburn.
• Viral URI.
Guttate Psoriasis
• Look for Strep.
• Pen VK 500mg BID.
• Topical mid potency
steroids such as TAC
0.1% cream.
• NBUVB , Sunlight.
• Do not use
Prednisone!
Photodermatitis
Phototoxicity
• Sunburn reaction, erythema,
edema.
• Direct tissue injury
• Occurs after first exposure.
Photoallergy
• Pruritic, eczematous lesions.
• Type IV delayed
hypersensitivity.
• Does not occur after first
exposure.
• Onset minutes to hours.
• Onset 24-48 hours.
• Large dose of agent needed
for eruption.
• Small dose of agent.
Phototoxicity
Photoallergic
Phototoxic agents
• Systemic:
Tetracyclines,
Phenothiazines,
Thiazides, Furosemide,
Sulfonylureas.
• Topical:
Furocoumarins: lime,
lemon, celery, tar.
Photosensitivity/Doxycycline
Photoallergic agents
• Systemic:
Quinolones,NSAIDs,
sulfonamides.
• Topical:
Fragrances.
Photocontact/Allergic Contact
Dermatitis
?
• At beach.
• Having a refreshing
drink with a twist
of lime.
Phytophotodermatitis
• Limes have
psoralens
containing
compounds that
are phototoxic.
• Oil of Bergamot
Phytophotodermatitis
• Initial onset erythema or blisters after contact
and sun exposure. May be absent.
• 48-72 hrs later hyperpigmentation at sites of
contact.
• May persist up to 4-6 weeks
Phytophotodermatitis
• Biting into lemon
• Squeezing limes
?
Allergic Contact Dermatitis-Mangos
• Mango skins have
urushiol which is
same as poison ivy
• Oil from skin of
mango drips onto
skin creating contact
dermatitis
Poison Ivy
• Leaves and vine can
cause rashes
• Any season
• Sensitivity varies from
person to person
• Three leaflets
Poison Ivy
• Look for linear blisters
or erythema
• Very pruritic
• Blister fluid is not
contagious
Poison Ivy
• New areas may
develop over time due
to small areas of
chemical contact
taking longer to react.
• Resin from plant
called urushiol can
oxidize and turn black
on the skin which is
called a “black lacquer
spot”
Treatment
• Ultra potent topical steroids if a localized area
such as clobetasol propionate 0.05%
• Systemic steroids often needed
• Medrol dose pack too little, and too short
• Prednisone 40-60mg with a slow taper over
12-18 days, maybe longer if reactivation
• Ivy Block etc. may help prevent the oils from
the plant getting to the skin by acting as a
barrier which you apply as a lotion prior to
potential contact
• Wash all clothes, tools, shoes, and gloves after
contact since resin may last for years even
when air dried.
Swimmer’s Itch
(clam digger’s itch)
Sea Bather’s Eruption
Swimmer’ Itch Sea Bather’s Erupt.
• Water:
fresh or salt
• Body part: uncovered
• Locale: North US and
Canada
• Cause: cercarial forms
of nonhuman
schistosomes(snails)
• Water: salt
• Body part: covered
• Locale: Florida and
Cuba
• Cause: larval forms of
marine coelenterates
(sea anemone, jellyfish)
Treatment/Prevention
• Swimmer’s itch: symptomatic Rx for itch.
Vigorous towel drying may prevent penetration of
the cercariae
• Sea Bather’s eruption: symptomatic Rx for itch.
Remove swimwear before shower since fresh
water may cause discharge of nematocysts. Heat
dry swimwear
Swimmer’s Itch
(clam digger’s itch)
Sea Bather’s Eruption
Tinea Versicolor
Tinea Versicolor
• Malassezia furfur
• Normal cutaneous
flora
• 2-8% US population
• Warm, humid
enviroment
• Very common in
tropical regions of
world
• Immunosupression,
Cushings disease
• Hyper and
hypopigmented
macules with fine
scale
• Hypopigmentation
caused by tyrosinase
inhibition
• Hyperpigmentation
caused by enlarged
melanosomes
• KOH: short hyphae
and spores “spaghetti
and meatballs”
Tinea Versicolor - Treatment
• Topical anti-fungals
• Selenium sulfide 2.5% lotion
• Oral ketoconazole 400mg
single dose, repeat in 1 week
• Fluconazole 200-400mg
weekly 2-4 weeks
• Itraconazole 200mg QD x 7
days
Pityriasis Rosea
Pityriasis Rosea
• Pruritic, oval, salmoncolored macules with
collarette scale
• Herald patch on neck
or trunk, then 1-2 wks
later smaller lesions
• Lasts approx. 12
weeks
Pityriasis Rosea
• Follows skin creases
• Can have atypical
cases which are more
papular, vesicular, or
widespread
Pityriasis Rosea
• Probable viral etiology, but no definitive data
• Clusters during spring common
• Not contagious
PR- Treatment
• Symptomatic for itch: antihistamines, topical
steroids
• UVB, sunlight helpful
Perioral Dermatitis
• Acneiform lesions.
• Erythema and scale.
• Common in women.
• Etiology unclear, but
topical steroid use
often the cause.
Perioral Dermatitis
• Perioral and perinasal
most common.
• Occasional periocular.
Treatment Perioral Dermatitis
• Avoid high potency topical steroids.
• If topical steroids have been used for longer
than 1 month prior to diagnosis, may need
to use a mild (1%) hydrocortisone cream to
prevent rebound flare.
Treatment Perioral Dermatitis
• Oral antibiotics: Doxycycline, and minocycline
good choices
• Topicals: Clindamycin lotion, metronidazole
gel, lotion
• Elidel and Protopic have shown some promise
Perioral Dermatitis
• Remember : topical
steroids are most
often the cause, not
the cure.
What is it ?
• Annular
• Raised scaly boarder
• Central clearing
• Pruritic
Tinea Corporis
Differential Diagnosis
• Tinea
• Nummular eczema
Nummular eczema
• Annular
• No central clearing
• Pruritic
What to do?
• KOH
• Look for other signs of eczema: dry skin, atopy,
h/o eczema
• If in doubt treat with topical antifungal first
• If you use topical steroid first, it will flare a fungal
infection
• Be careful with betamethasone/clotrimazole
combination
• Never more than 2 weeks
• The betamethasone component too potent for most
fungal infections, and high risk of steroid atrophy
• Worsening tinea
• Striae
Treatment
• Topicals: Econazole, Ketoconazole etc….
• Keep dry
• Be patient
Tinea Capitis
 Most common under
age 15.
 It is rare in adults.
 Sebaceous gland
maturity is protective
against Tinea in scalp
• Scale, loss of hair,
other siblings with
same
• If healthy adult with
similar clinical picture,
think psoriasis or
seborrhea
Tinea Capitis
 US: Trichophyton
tonsurans most
common
 Europe:
Microsporum
canis and
audouinii most
common
 Woods lamp not
always helpful since
Trichophyton do not
fluoresce.
(microsporum do)
 KOH and culture to
diagnose
Treatment of Tinea Capitis
• Systemic rx needed
• Griseofulvin ultra microsized
250mg bid 8-16wks until clear
• Griseofulvin Suspension 20-25
mg/kg/day for younger children
• Lamisil
10-20kg, 62.5mg/d
20-40kg, 125mg/d
>40kg, 250mg/d
KERATOSIS PILARIS
Keratosis Pilaris
• Hyperkeratotic
erythematous
follicular papules
• Cheeks, arms, thighs,
occ. trunk
• Genetic: Autosomal
Dominant
Keratosis Pilaris
• Cheeks improve at
puberty. Other sites
persist
• Improves in summer,
worse in winter
• Treatment
– Ammonium lactate 12%,
salicylic acid 6% , urea
40-50%.
– Topical retinoids
occasionally
Pityriasis Alba
• Don’t confuse Pityriasis
alba with Tinea Versicolor
• Pityriasis alba more often
associated with atopic
dermatitis
• Hypopigmented,
erythematous dry
patches. Face and arms.
Pityriasis Alba Treatment
• Emollients and
keratolytics:
Ammonium lactate
12%, Salicylic acid
6%.
• Low potency topical
corticosteroids: 1%
HC, Desonide 0.05%.
Lichen Planus
• Purple, pruritic
papules
• Wrists, legs, trunk,
genitals, and scalp
• May hyperpigment
as it resolves
• White streaks over
surface – Wickham’s
striae
• Adults > children
• Oral involvement
with whitish lacy
patches
• May ulcerate
• Risk oral SCC
• Nail LP may cause
chronic changes
• Scalp LP called
Lichen Planopilaris.
• May cause scarring
alopecia
• Immune mediated.
• May be associated with
Hep C
Treatment LP
•
•
•
•
•
•
Topical corticosteroids
Oral steroids if severe
UVB, PUVA
Oral Retinoids
Protopic ointment 0.1% for oral disease
Hydroxychloroquine, Mycophenolate Mofetil,
and recently Pioglitazone for Scalp LPP
SCABIES
(Sarcoptes Scabiei var Hominis)
SCABIES
• Very pruritic
• Burrows and
erythematous papules
• Nipples, areola
• Glans penis, scrotum
• Finger webs, axilla
• Female mite causes
symptoms. Male dies after
fertilization
• 5-15 mites per patient
• Ova or feces may be
found
• Crusted (Norwegian)
scabies has hundreds
to millions of mites
• Live up to 48hrs off host
• Nursing homes, group
homes etc.
• Scraping may be negative
If your patient has:
• Chronic itch
• Worse at night
• Others with itch in
household
• No other obvious
cause
• Be Suspicious of
Scabies
Scabies Treatment
• 5% Permethrin cream (Elimite) neck to toes (occasionally
face and scalp ) overnight. Repeat in 1 week
• Treat others in house
• No need for lindane
• Change bedding after each treatment
• Ivermectin 150-200 mcg/kg single dose. May repeat in 1
week
Dermatology
“Doc, I Have This Rash…”
Joseph S. Baler M.D.
September 7, 2013