Lectures 1-3 Flashcards
Are the red scaling patches of atopic dermatitis well defined or ill defined?
Ill defined
What are some long term complications from SJS/TEN?
Scarring/contracture of skin
Vision loss/eye problems
Pulmonary complications
What is onychomycosis?
Infection of the nail by:
Fungus
Yeast
Non-dermatophyte molds
What color is tinea versicolor
Variety of colors!
Hypopigmented
Hyperpigmented
Erythematous
Clinical manifestation of melanoma?
Most de novo, with some arising from pre-existing nevus
Usually asymptomatic
Pigmented papule, plaque or nodule
DDx for BCC?
Sebaceous Hyperplasia- enlarged oil gland with central clearing.
Fibrous Papule-benign angiofibroma. Skin colored/pink papule on nose. No telangiectasia and lacks pearly texture.
On infants, is atopic dermatitis on the flexor surfaces or extensor surfaces?
Starts on extensor surfaces then moves to flexor surfaces once they start crawling/walking
Burning stinging pain on hands is associated with which skin condition
Irritant contact dermatitis
Presentation of proximal subungual onychomycosis
Starts near cuticle and progresses out
Uncommon
Usually seen in VERY immunocompromised ppl (like AIDS)
Is sweat isotonic or hypotonic?
It starts isotonic with plasma, but due to electrolyte reabsorption in duct, it becomes hypotonic
What is intertrigo
Any inflammatory condition of two closely opposed (intertriginous) skin surfaces
-often due to candida species
What might a patient report before a drug eruption?
A prodrome involving fever, malaise, flu-like symptoms
Which is more common, distal or proximal subungual onychomycosis?
Distal, by far
Why does tylenol get blamed for SJS/TEN?
Because people take tylenol for the prodrome they feel for 1-3 days before rash erupts and they blame it on that.
Which layer of epidermis has keratinization?
Stratum granulosum
Some cancers start here
Tx of nondermatophyte onychomycosis
Oral itraconazole
6wks for fingernails
12 wks for toes
What skin condition is associated with occupations like bartenders, hairdressers, cleaning ladies?
Irritant contact dermatitis
What does SJS/TEN look like before skin starts sloughing off?
TENDER red and purple macules with blisters
Clinical presentation of tinea corporis
Pruritic, annular, erythematous plaque
(Itchy, red, round plaque)
Central clearing **
RAISED advancing border (touch it)
What does a drug eruption look like
Erythematous macules and papules
Measles-like
Diagnosis of tinea versicolor
KOH prep Woods lamp (1/3 of them glow yellow-green) not very useful
What is Leser-Trelat sign?
Sudden onset of multiple SKs with inflammatory base
+skin tags
+acanthosis nigricans
=possible association with GI and lung cancers
What is the dominant symptom of allergic contact dermatitis?
Itch
Difference between acute and chronic tinea pedis?
Acute-self limited, intermittent, recurrent infection. Itchy painful blisters following sweating with 2* staph infections common.
Chronic- slowly progressive infx that persists indefinitely. Interdigital fissures and erosions/scales between toes (especially 3rd and 4th)
Clinical presentation of tinea capitis?
Scaly patches with hair loss
Hair loss with black dots
Widespread scaling w. Minimal hair loss
Kerion (boggy, edematous, painful plaque)
Favus (multiple cup shaped yellow crusts aka scutula)
Who is at risk for scabies infection
EVERYONE
Most common cell in epidermis?
Keratinocytes
Risk factors for Malignant melanoma?
Genetic predispostion Prolonged UV exposure Fair skin/hair/eyes Immunosuppressed 6+ atypical nevi 26+ regular nevi
How long after taking a drug will a drug eruption occur
5-14 days
What are 5 common drugs that can cause drug eruptions?
Penicillins Cephalosporins Sulfonamides Carbamazepine Phenytoin
What types of cells are in the hypodermis (subcutis)
Fibroblasts, adipose, and macrophages
What is distinctly different about SJS/TEN vs drug hypersensitivity syndrome?
SJS/TEN involves mucous membranes
Where is it NOT OK to use high potency steroids?
Face
Skin folds
Genitalia
Risk factors for tinea versicolor
Tropical climate
Adolescents
Hyperhidrosis
Immunosuppression
What are the 2 types of severe cutaneous adverse reactions?
- drug hypersensitivity syndrome
- Stevens-Johnson/Toxic Epidermal Necrolysis
Where does tinea cruris begin?
Inguinal fold
What area is usually spared by atopic dermatitis in children?
DIAPER AREA
Treatment for solar lentigo?
No treatment required
Treatment of tinea versicolor
Topical: Clotrimazole x 2 weeks Selenium sulfide x 1 week (shampoo, lotion, foam) Zinc pyrithione shampoo x 2 weeks Systemic: Itraconazole
Appearance of tinea versicolor
Macules, patches, plaques on trunk & arms
Often have a fine scale
Can coalesce into a big patch
Might itch
What is the gold standard treatment for atopic dermatitis?
Petroleum (Vaseline) applied twice a day and right after bathing
Goal is to hydrate the skin with emollients
What are important features (not essential) of atopic dermatitis that would add support to your diagnosis?
Atopy (predisposition to developing allergic hypersensitivity rxns)
Early age of onset
Xerosis (dry skin)
What is a solar lentigo
“Age spot”
Flat, brown macule
Often in groups
Well circumscribed
What does nummular eczema look like?
Coin shaped red lesions
Features of nodular melanoma
AGGRESSIVE
Nodule is INFLAMED AND FRIABLE
Rapid vertical growth
Who should get systemic treatment for tinea corporis
- immunocompromised
- failed topical tx
- tinea corporis gladiatorum (no participation for 10-15 days) (athletes are eager to get back)
What does irritant contact dermatitis look like?
Dry, red chapped skin with fissuring
Keratosis Pilaris is a disorder of what
Keratinization
Keratinocytes don’t slough off right
Associated signs of tinea capitis?
- Swollen cervical nodes
- Dermatophytid rxn-eczema like rxn after starting tx
- Erythema nodosum- leg lesions (rare)
From where does BCC arise?
Basal layer of epidermis (least concerning)
What will happen if you treat tinea corporis with a steroid?
It gets worse (mojocchi’s granuloma)
+you waste money
What is a positive Nikolsky sign?
Skin blisters and separates as a result of gentle mechanical pressure on the skin
Features of superficial spreading melanoma?
Most common subtype (70%) Confined to epidermis Grows out not up Younger people Men:back Women: back and legs
Where is atopic dermatitis usually found in infants?
CHEEKS
Trunk
Extremities
What skin condition is an example of a DELAYED hypersensitivity reaction
Allergic contact dermatitis
How is SJS/TEN diagnosed?
Clinically initially: blisters in mouth, been feeling feverish, has the rash…
Then,
biopsy looking for 2* infections
Culture blood, wound, mucosal lesions
Diagnosis of actinic keratoses?
Typically based on appearance and texture.
If over 1cm, rapidly growing, ulcerated or painful, you should biopsy.
If over 6mm, consider SCC in situ.
Clinical presentation of tinea cruris
- WELL MARGINATED, scaly round plaque with a RAISED border
- extends from inguinal fold to inner thigh
- scrotum typically spared
Presentation of white superficial onychomycosis
- starts w dull white spots on nail
- spreads OUT over entire nail
- soft lesions that can be scraped for sampling
Poison ivy, oak, and sumac contain what oil that causes allergic contact dermatitis 12-24hrs later?
Urushiol oil
Is irritant contact dermatitis an immune response?
No
Most common type of skin cancer?
Basal cell carcinoma
What effect does more melanin have on skin tone and vitamin D production?
Darker skin tone
Difficulty synthesizing vitamin d
Where is the Basement Membrane Zone
Between the epidermis and dermis.
It is a barrier for malignant cells.
What distinguishes SJS from TEN?
SJS is less than 10% surface area
TEN is more than 30% surface area
(SJS/TEN overlap if 10-30%)
Where is dyshidrotic eczema found
Hands, sides of fingers, palms/soles
Treatment of Tinea capitis
Systemic anti fungal therapy- Griseofulvin x 6-12 weeks
Tx of choice for Microsporum genus or EMPIRIC tx
Treatment of tinea pedis
Clotrimazole x 4 wks (topical)
itraconazole (oral) for chronic/extensive disease.
+Burow’s wet dressings for vesiculation/maceration 20 min 2-3x/day
+foot powder/better shoes etc
(SIMILAR to tinea corporis but typically requires longer tx bc its stubborn)
4 layers of epidermis
Stratum corneum Stratum lucidum *palms/soles Stratum granulosum Stratum spinosum Stratum basale
“Come lets get sun burned”
Dermatitis and Eczema are used interchangeably, but dermatitis is most often used to describe ____ causes
Exogenous.
Ex: irritant contact dermatitis, allergic contact dermatitis, seborrheic dermatitis etc
How do you treat pubic lice?
Permethrin 1%, repeat in 10 days (same stuff as for scabies but less potent)
Treat sex partners
Take detailed sexual history because they have another STI 30% of the time
Management of multiple actinic keratoses?
Field treatment:
- photodynamic therapy
- Topical 5-FU
- Imiquimod (Aldara)
Can sarcoptes scabei mites live away from a host
Yes for 3 days
What is the treatment for dyshidrotic eczema?
- Reassurance (2-3 wks spontaneous remission)
- topical steroids
- wet dressings (Burows soaks)
Concern with actinic keratoses?
Precancerous. 8% progress to SCC.
What is the treatment for eczema herpeticum?
Prompt treatment with an antiviral (acyclovir/valacyclovir)
its herpes
Hallmark of Actinic Keratosis
Feels like sandpaper
Where is atopic dermatitis usually found on older children/adults?
Flexor surfaces and backs of hands/feet
Neck
How do you treat lichen simplex?
You have to stop the itch-scratch cycle!
- high potency topical steroids (thick skin)
- moisturizers
- SSRI’s (histamine effect)
- hydroxyzine or doxepin for sedative effect that prevents nighttime scratching
Colloquial name for tinea pedis?
Athletes foot
What does Keratoacanthoma look like?
RAPID GROWTH over 6-8 was
Round, flesh colored nodule with CENTRAL KERATIN PLUG
Treatment of tinea corporis
Clotrimazole x 2 wks (at least)
Systemic tx for special cases: Itraconazole
What is a Type IV pathogenetic mechanism?
Delayed sensitivity
24-48 hrs after exposure. Cell mediated immunity
What is the concern with a lesion that never heals?
SCC
What causes tinea versicolor
Overgrowth of NORMAL fungal skin flora that transforms into the mycelial form
What kind of cell gives rise to Squamous cell carcinoma?
keratinocytes
How is atopic dermatitis diagnosed?
Clinical diagnosis based on history, morphology and distribution
What percentage of Rxs written for a new medication cause a drug eruption
2%
What drugs do you treat candidal intertrigo with
Topical nystatin
Itraconazole (oral) for resistant/severe cases
What is the pathognomic sign of scabies?
Burrow
Other treatments for tinea cruris?
- treat concomitant tinea pedis and/or onychomycosis
- daily talcum powder
- avoid tight clothing
- weight loss
- avoid hot baths? (Hot water might irritate skin)
Clinical presentation of BCC
Pearly, shiny
Telangiectasia
Rolled border
Where does sweat from apocrine glands go?
Into hair follicles. it is odorless at first. Becomes smelly when bacteria eats it.
Management of isolated actinic keratosis?
- Isolated lesion: CRYOTHERAPY or surgical intervention
- May resolve spontaneously, but could reoccur
3 main layers of skin
Epidermis
Dermis
Hypodermis
What medications commonly cause SJS/TEN?
Allopurinol
Anticonvulsants (phenobarbital, phenytoin, carbamazepine, lamotrigine)
Sulfonamides (Bactrim)
NSAIDs
Presentation of distal subungual onychomycosis?
- white/brown/yellow starts at distal corner and spreads toward the cuticle
- usually starts with big toe
- end of nail breaks, exposing nail bed
How is scabies transmitted?
Direct contact
What is included in the atopic triad?
Group of 3 diseases that all come together
Atopic dermatitis
Allergic rhinitis
Asthma
(In this order known as atopic march)
Features of acral lentiginous melanoma
AFRICAN/ASIAN ancestry (dark skin) Spreads out, then grows up Usually males Large due to delay in dx Often palmar, plantar, or subungual
BOB MARLEY
When is atopic dermatitis usually diagnosed?
before age 5
60% are in the first year of life!
What two things make dyshidrotic eczema worse?
Emotional stress and hot weather
Features of Lentigo maligna
Common in OLD PEOPLE
Slowly grows out, but rapidly grows UP
Usually remains more superficial
What is the main prescribed treatment for atopic dermatitis?
Topical steroids, increasing the potency accordingly based on the severity of the eczema
What condition is associated with a positive nikolsky sign?
SJS/TEN
What does dishydrotic eczema look like?
Tapioca.
Deep seated vesicles that coalesce and rupture.
Considerations for tx of onychomycosis
Topical medications usually don’t work
HIGH RATES of failure/recoccurence
What type of reaction is allergic contact dermatitis?
Delayed-type hypersensitivity reaction. CELL MEDIATED.
TBSA of: Head: 1 arm: 1 leg: Back: Torso: Genitals:
Head: 9% 1 arm: 9% 1 leg: 18% Back: 18% Torso: 18% Genitals: 1%
Reasons to treat onychomycosis
- history of cellulitis
- diabetic
- cosmetic
- pain/discomfort
What are the essential features that must be present in order to make a diagnosis of atopic dermatitis
- Pruritus
2. Eczema with typical morphology and age specific patterns, as well as a chronic or relapsing history.
What complication of atopic dermatitis involves thickening/deepening of skin lines?
Flexural lichenification
Pharmacological treatment of tinea cruris
Topical: clotrimazole
Resistant cases: oral itraconazole
What are important questions to ask the pt in the evaluation of any rash?
Who What When Where Why Associated symptoms (itch, pain,fever) STI risk
What can you prescribe for contact dermatitis?
Topical steroids for 1-2 wks
But you should consider prednisone if it involves the face or more than 20% body surface area (.5-1mg/kg)
What is a Type III pathogenetic mechanism?
Immune Complex
Antigen-antibody complexes cause tissue inflammation. IgG or IgM.
Topical steroids are grouped based on potency. Which group is the most potent?
Group 1 is super high potency
Group 7 is least
What does seborrheic keratosis look like?
“Barnacle of aging”
-Tan to black, Warty, waxy, “stuck on” appearance
- Well demarcated, oval/round/irregular shape
- Common on chest back head and neck
Dermatitis and eczema can be used interchangeably, but eczema is more often used to describe _____
Endogenous disease
Ex: atopic eczema, nummular eczema, etc
Presentation of candidal intertrigo?
- erythematous, macerated plaques and erosions
- Satellite papules/pustules
- fine peripheral scaling
So if you can’t put steroids on face or in skin folds, what topical treatment can you prescribe for atopic dermatitis?
Topical calcineurin inhibitors
Which is a cream/ointment that ends in “-crolimus”
(Trade names: Elidel or Protopic)
What group of people has a 100-fold increase of SJS/TEN incidence?
HIV+
Pharm treatments of scabies
Topical or systemic tx:
Permethrin 5%-slather all over once and then again 10-14 days later
OR
Oral ivermectin-single dose repeated two weeks later
What type of antibodies are associated with atopic dermatitis?
IgE (the ones attached to mast cells)
What causes lichen simplex chronicus/neurodermatitis?
excessive scratching or rubbing
Who is most at risk for getting tinea capitis?
Children,
African-Americans
Decreased personal hygiene
Overcrowding
What should pt education about scabies involve?
- postscabetic itch can persist for 2 wks
- close contacts and housemates must be treated as well
- wash linens in hot water and dry under high heat
- oral antihistamines and emollients can provide relief
ABCDEs of melanoma?
A-asymmetry B-border (uneven borders bad) C-color (multiple colors bad) D-Diameter (bigger than .25 inch bad) E-evolving
Other name for tinea versicolor
Pityriasis versicolor
Who is more likely to get tinea corporis?
Caregivers for children with tinea capitis
Athletes w. Skin to skin contact (tinea corporis gladiatorum)
Immunocompromised ppl
What are the most common types of drug eruptions (appearance-wise)?
Morbilliform (measles like)
Exanthematous
-basically a widespread measles-like rash
Management of keratoacanthoma?
Majority resolve spontaneously in 6-9 months
BUT you are too stupid to differentiate from SCC so you will biopsy these.
What is Norwegian scabies
Crusty, fissured, extreme scabies in the immunocompromised
Fissures provide route for bacterial infection too
What causes scabies
Sarcoptes scabei mite
Tx of dermatophyte onychomycosis
Oral terbinafine
6wks for fingernails
12wks for toes
What skin condition causes a dry, leathery appearance with exaggerated skin markings and pigmentation?
Lichen simplex chronicus
If a kid has a rash all around their lips cause they lick them all day, what condiiton is that’/
Irritant contact dermatitis
What are the fatal complications of SJS/TEN?
Infection of skin, lungs, mucus membranes, septicemia **
Dehydration & malnutrition GI ulceration/perforation Shock/organ failure Thromboembolism Acute respiratory distress syndrome
Most common cause of onychomycosis in fingernails
Yeast, usually Candida albicans
May cause chronic paronychia-infection of nail margin/cuticle
Nickel, latex, cosmetics, preservatives, and neomycin can cause what skin condition?
Allergic contact dermatitis
What is the most common dermatophytosis in the world?
Tinea pedis
Side effects of topical steroids
Pigment changes Atrophy Striae Bruising Tenlangiectasias
Clinical presentation of SCC?
Scaly Exophytic (grows out) Indurated (hardened) Friable Often appears warty
What are some other presentations of chronic tinea pedis?
Moccasin ringworm-sharp demarcation around whole foot w/accumulated scale in skin creases.
Tinea manuum-two feet, one hand
What type of reaction is drug eruptions
TYPE IV DELAYED TYPE IMMUNE REACTIONS
CELL MEDIATED
With SJS/TEN, should the pt keep taking the offending medication?
No lol
4 types of melanoma?
Superficial spreading
Nodular
Lentigo maligna
Acral lentiginous
Is tinea versicolor contagious
No
Where are Merkel cells and what do they do?
They are in the epidermis and are for perception of light touch. Abundant in fingertips.
What is a dermatophyte?
Fungus that causes infection
Tinea capitis, tinea corporis, tinea cruris, tinea pedis
What type of reaction is atopic dermatitis?
Type 1 Hypersensitivity
IgE Mediated
How do you know if you have SCC in situ?
Only from biopsy
What is a Type I pathogenetic Mechanism?
Immediate/anaphylaxis
Allergic reaction involving IgE, Mast cells, basophils, hives, laryngeal spasm, edema
What are the 2 types of contact dermatitis?
Allergic Contact Dermatitis
Irritant contact dermatitis
Which type of contact dermatitis is associated with papules, blisters and edema?
Allergic contact dermatitis
Treatment of melanoma
WIDE SURGICAL EXCISION IS GOLD STANDARD with 2cm of clear margins
-lymph node biopsy,
Chemotherapy, immunotherapy, gene therapy, follow up every 3 months
What is the colloquial name for tinea cruris
Jock itch
What is the most common type of contact dermatitis
irritant contact dermatitis (80%)
How is tinea capitis acquired?
Direct contact with infected person, animal, or fomite
How does Mohs surgery affect recurrence rates?
Lowers recurrence rates
Higher cure rates than excisional biopsy
What two bacteria can cause fatal SJS/TEN complications like septicemia and pneumonia?
S. Aureus
P. Aeruginosa
How to diagnose scabies?
- visualization of the burrow w naked eye
- microscopic identification of the mite, eggs, or poop pellets
- dermatoscope can be used to actually visualize mites
What is a Type II pathogenetic mechanism?
Cytotoxic
Involves IgG or IgM
Reaction to surface antigen and activate complement
How would you empirically treat fingernail vs toenail onychomycosis?
Toes are USUALLY dermatophyte, so you would go with terbinafine x 12 wks
Fingers are USUALLY yeast (nondermatophyte), so you would go with itraconazole x 6wks
(Both are oral)
What oral meds can be taken for atopic dermatitis?
Oral antihistamines for itching
Antibiotics for 2* infection
Oral steroids for BAD cases
Scalp Back of neck Wrists Forearms Lower legs Genitals esp scrotum Are common areas for which skin condition?
Lichen simplex chronicus
What are the symptoms of drug hypersensitivity syndrome?
High Fever
Rash (morbilliform)
Internal organ involvement
Hematological weirdness (labs) Lymphadenopathy
To what disease does the phrase “The itch that rashes” refer to?
Atopic dermatitis
-vicious cycle of scratching that makes it worse
Where are apocrine sweat glands
Axillary and Anogenital regions
Concerns with onychomycosis?
- primarily cosmetic
- can be painful
- increases risk of other infections, esp in immunocompromised
Management of Seborrheic Keratoses?
Biopsy if ISK looks really nasty
Reassure pt it is benign
Consider removal for cosmetic reasons, or if irritated (under bra strap, etc)
(Usually cryotherapy, but can be shaved off or curettage and electrodessication
In what skin layer does the female scabies mite burrow and lay eggs
Stratum corneum
From where are Langerhans cells derived?
Bone marrow
-“macrophages of skin”
SCC treatment?
Usually surgical. Either wide excision or Mohs.
C&D or cryotherapy on an AK may reveal it was SCC in situ.
Usual areas affected by candidal intertrigo
Groin, mammary/abdominal folds, web spaces, axilla
