Derm Obj with more detail (derived from Enoch's cards) (15%) Flashcards
What are the factors associated with development of acne vulgaris?
Increased sebum production
Follicular hyperkeratinization
Proliferation of cutibacterium acnes
Inflammation
What triggers acne in puberty?
Androgen stimulation of pilosebaceous unit
Changes in keratinization at follicular orifice
Hormones and keratinization
When does the follicular ostium dilate in acne?
Comedo formation
When does rupture of the follicular wall occur in acne?
Nodule/cyst
Which gender usually has more acne?
Women
Specifically in adult women, what kind of acne papules are found and where?
Deep seated & tender red papules along the mandibular jaw.
What are drug-induced acneiform eruptions usually composed of?
Monomorphic inflammatory papules and pustules
What is mod for comedone #?
20-100
above = severe
below = mild
What is mod for papules/pustules #
15-50
above = severe
below = mild
What is mod for nodule #?
<5
> 5 = severe
What could itchy acne be and what do we do then?
If itchy, could be papules that we can do KOH prep on.
Check for pityrosporum folliculitis (tx with keto shampoo)
MOA of retinoid
Decreases cohesion and increases turnover of epidermal cells
stops skin from being sticky and increases cellular death so that there is not time for acne to grow
t/f you can have retinoids in preggo?
FALSE
your patient has taken a lot of abx and you are worried about antibiotic resistance, so you consider ____ for treatment of their acne
benzoyl peroxide (BPO)
No bacterial resistance
SE of benzoyl peroxide (BPO)
Skin irritation
Bleaching of hair/clothing
B = Bleach
In what type of acne is topical abx indicated?
Papulopustular
think bacteria d/t puss
1st line topical abx
Clindamycin or erythromycin (my son has acne)
Often combined with BPO
when are oral abx indicated for acne?
Moderate acne: inflammatory papules or deep-seated lesions
20-100 comedones
15-50 papules/pustules
< 5 cysts
What are the oral abx for acne?
remember, indicated for moderate acne
Doxycycline
Minocycline
-cycline
3 month tapered course
MOA of oral abx for acne
inhibition of C. acnes
CI for tetracylcines used as oral ABX for acne
preggo or young
can use macrolides (mycin) if this is an issue
If a patient is not able to have -cycline or -thromycin for oral abx treatment for mod acne, what are the 2nd line options?
Bactrim DS
Keflex (safe in preggo but not that effective)
Treatment of severe resistant nodular/cystic acne
Isotretinoin (accutane)
last resort monotherapy
MOA of isotretinoin (Accutane)
Same as others: inhibition/decrease in C acnes
Apart from being CI in preggo, what is another CI of isotretinoin?
Use with an oral tetracycline
-cycline
You must monitor CMP/lipids this often () with isotretinoin and stop or use a statin if lipids reach ()
monthly
700-800
What is interesting regarding your blood when you are on isotretinoin?
You may not donate it
What is perioral dermatitis and MC demographic?
Discrete erythematous micropapules
MC in females
RFs for perioral dermatitis
Topical fluorinated glucocorticoids + inhalers
Fluroinated toothpaste
OCP
Fluorine
patient will likely be on one of these in a case scenario
Tx for perioral dermatitis
D/C Steroids
What is the most common form of alopecia?
Androgenic alopecia
Aka sex pattern hair loss
What is the underlying pathophysiology of androgenic alopecia?
____ are regressed into _______ hairs due to _____.
Terminal hairs are regressed into indeterminate/vellus hairs due to androgens.
Terminal hairs are affected by hormones!
What androgenic alopecia classification describes females vs males?
Females = Ludwig-Savin
Males = Norwood Hamilton
Women wear wigs
Alexander Hamilton was a man
What hormone specifically causes androgenic alopecia and the long-term result of exposure to it?
DHT
Successive cycles will produce shorter and thinner hairs
If I do a biopsy of androgenic alopecia, what do I expect to see?
Telogen phase & atrophic follicles
Minoxidil is typically the treatment for androgenic allopecia, but this medication () can be used for men and this () can be used for women
Finasteride for men (5-alpha-reductase inhibitor that inhibits conversion of T to DHT)
Spironolactone for women (prevents DHT from working but does not have direct affects on T)
what is the triad of atopy?
- Atopic dermatitis
- Allergic rhinitis (hay fever)
- Asthma
3 As
What is the cycle of atopic dermatitis?
Dry skin
Pruritis
Increased inflammation (from itching)
Lichenification
What are the three pathophysiologic causes of dry skin d/t atopic dermatitis?
Impaired filagrin production
Reduced ceramide levels
Increased trans-epidermal water loss
what inflammatory markers are expressed in atopic dermatitis?
IL-4
IL-13
Hallmark sign of atopic dermatitis
Intense pruritis
Leading to lichenification as you keep scratching. Also can lead to 2ndary infections.
Presentation of someone with atopic dermatitis
Chronic: periorbital plaques
Hyperpigmentation
Hyperlinear palms
Keratosis pilaris
Hx of allergies
What is the primary thing that clues you into atopic dermatitis?
Hx and FHx
What is the tx for atopic dermatitis?
Gentle cleansers
Low strength steroids
How do you manage striae in atopic dermatitis?
Ointment without preservatives
Damp skin or under occlusive dressings
AVOID soap except in body folds
Cream for localized dermatitis
Low potency: desonide BID
Medium potency: Triamcinoline/mometasone/fluocinolone BID
Non-steroidals (only use if >2y): Tacrolimus/pimecrolimus/crisaborole
Systemic tx for atopic dermatitis
Dupulimab SC
Tx for pruritis in atopic dermatitis
Antihistamines
makes sense
How do you differentiate between irritant contact dermatitis vs allergic contact dermatitis?
ICD: confined to area, sharply marginated, never spreads
ACD: spreading, type IV HSR
your male patient comes in with dermatitis of the face, neck, upper chest, forearms, and palms - what type of dermatitis do you suspect?
Airborne contact dermatitis
sun exposed skin
Diagnosis of contact dermatitis
Hx
Patch testing ((+) still requires you to clinically correlate)
Do not use skin prick test, which only tests Type 1 HSR
Patch testing is not the same as skin prick testing
What is the underlying physiology of allergic contact dermatitis?
____, which bind to a carrier and cause a Type _____
Haptens, which bind to a carrier and cause a Type IV HSR
Re-exposure to a substance already sensitized to
apart from avoid offending agents, how do you treat allergic contact dermatitis pharmacologically?
Steroids (topical/oral)
What non-pharmacological therapy can help with contact dermatitis?
PUVA Phototherapy
psoralen utraviolet A
what is miliaria?
blocked sweat ducts
what type of dermatitis can miliaria cause?
Diaper dermatitis
Apart from barrier creams and targeting the offending agent, this patient education for bathing is important for diaper rash
Dry well
Fungus loves a wet, warm environment
What is ectothrix?
A grey patch with a scaly appearance
Hair shafts are broken off and brittle
An infection OUTSIDE of the hair shaft
for tinea capitis
What is endothrix?
Black dot appearance
Infection within the hair shaft
for tinea capitis
MC demographic for tinea capitis
AA children
How does non-inflammatory tinea capitis appear?
Scaling
Pruiritis
Alopecia
Adenopathy
Gold, mercury, and hep C are associated with this skin condition
Lichen Planus
How does inflammatory tinea capitis present?
Painful
Tender
Alopecia
How do the black dots appear in tinea capitis?
and MCCs
Broken off hairs => swollen shafts
Diffuse and poorly circumscribed
MCC: T tonsurans or violaceum
TVs in the house (endothrix is inside)
What does KOH prep show for tinea versicolor?
Hyphae and budding yeast spaghetti and meatballs
very colored
What are the 3 common types of verrucae seen in kids?
Verruca vulgaris: common (very) wart
Verruca plantaris: plantar wart
Verruca plana: flat wart (plain wart)
Dermoscopy with oil of these small, flat-topped papule has white lines around it. What are these white lines and what condition is it?
Whickham striae seen in Lichen Planus
How does verruca vulgaris present?
1-10mm papules
Isolated or multiple
Red and brown spots: thrombosed papilla capillary loops (seen on dermatoscope)
Jetliner with a trail
Dermoscopy finding for scabies
MCC of verruca vulgaris
trauma, hands/fingers/knees
How does verruca plantaris present?
Shiny plaques with a rough, hyperkeratotic surface
Thrombosed capillaries
Skin lines decrease
Usually uncomfortable
Tender
reminds me of a cigarette butt
of the foot
How does verruca plana present?
Sharply defined
1-5mm
Flat surface
Skin colored or light brown
Round, oval, polygonal, or linear
MC location of verruca plana
face, beard, dorsa of hands and shins
Management options for verrucae
**Salicyclic acid
**Cryotherapy
Imiquimod
Cantharidin (blister beetle)
Electrosurgery + vacuum to prevent aerosolization
Podofilox not mentioned, maybe cause it doesn’t really spread?
What does SA do?
Desquamation of hyperkeratotic epithelium
10-30% conc for small
40% conc for big lesions
What else should you do when applying SA?
Sanding/filing
What is cantharidin?
What is cantharidin?
Blister beetle substance, which causes a blister on the wart.
Where is pediculosis capitis MC and how does it present?
Lice
MC in schools, day-cares, SNFs, dorms, prisons
Intense pruiritis of the scalp
MC in white school aged girls/mothers
Warmer months
What does a louse look like vs nits?
Louse 1-3 mm long, flattened brownish-gray, 3 pairs of legs and claws
Nits are 1 mm and opalescent (eggs)
Humanus are in clothing, capitus on hair shafts
lifespan of a louse (lice)
14-18 days
What do lice and nits do to the scalp? What does microscopy show?
Mauculae cerulae or purpuritic stains may suggest infestation
Occipital lymph node involvement
Microscopy shows an oblong structure attached to hair an an acute angle with a breathing appartus at its superior end
Diagnostic pearls for pediculosis capitis
Pyoderma + occipital/cervical LAN suggest infestation
Nits are oval and tenacious; they stay stuck
Nits fluoresce under Wood’s lamp
Best tests for pediculosis capitis
Microscope
Wood’s lamp of nits
Management of pediculosis capitis
Permethrin has increasing resistance
Manual combing via fine comb
Should you treat a kid with empty nit cases?
No
Only live lice or eggs
OTC tx for pediculosis capitis
Permethrin (Nix): dry hair then rinse after 10m. Repeat in 1-2 weeks
Pyrethrins + piperonyl butoxide(RID, Pronto): same as above
Rx tx for pediculosis capitis
Spinosad/Natroba: children > 4y First line tx
Malathion lotion
Ivermectin lotion: 6 months or older & not preggo
Tx for eyelid involvement of pediculosis capitis
Petrolatum BID for x8d
What causes scabies and MC mode of transmission?
Mite: Sarcoptes scabiei var. hominis
MC: Direct contact
fomite spread is rare
Overview of scabies
10-20 mites per infestation
Extremely pruiritic 2-6 weeks later
Persists without tx!
Presentation of scabies and where it most often occurs (how does this differ from lice?)
Worse at night
Diagnostic sign: fine, thread-like line with tiny black speck at the end.
Small, erythematous papules
Rarely on head or neck
lice is most often on head (head lice)
scabies is MC on the shins
Who is crusted scabies/norwegian scabies MC in?
Immunocompromised
Institutionalized
What is crusted scabies like?
Thousands to millions of mites
Tx of crusted scabies
Topical Permethrin 5% overnight
+
Oral ivermectin x5 dosing
Best tests for scabies
Scabies prep via scraping and microscopy and mineral oil
Add on KOH for crusted scabies
Management of scabies
First-line: permethrin 5% or Rid
Last resort: Lindane (Avoid in crusted)
Oral ivermectin (2nd line, 0.2mg/kg/d)
What is the MCC of Pityriasis Rosea?
HHV6 & 7
spring/fall
Herald patch on the trunk
or Christmas Tree Rash
what occurs first - christmas tree rash or herald patch for Pityriasis Rosea?
herald patch followed by christmas tree rash 1-2 weeks after
Describe the exanthem associated with Pityriasis Rosea
Fine scaling papules and patches
Dull pink, salmon red
The Ps of Pityriasis = papules/patches
What is used in the tx of Pityrasis Rosea? (4)
Oral antihistamines
Topical antipruritic lotions (Sarna)
Topical Triamcinolone BID x 4 weeks
Oral steroids
antihistamines
triamcinolone = tree
What is the MCC of Lichen Planus?
idiopathic
we don’t know
What kind of condition is Lichen Planus?
Inflammatory Dermatosis of the skin +/- mucuos membranes
Acute or chronic
What does Lichen Planus look like?
Flat topped papules
Annular, purple pruritic
kinda look like RBCs to me
Where does Lichen Planus tend to occur?
Wrists (flexor)
Lumbar
Shins
Scalp
Penis
Mouth
Which Lichen Planus type involves cicatricial/scarring alopecia?
Follicular
think hair follicles
Which Lichen Planus variant is associated with Bullous Pemphigoid?
Vesicular
think of how vesicles progress into bullae
Involvement of this area with Lichen Planus is concerning?
Mouth
If Lichen Planus occurs in the hair and nails, what may happen?
Scarring alopecia
Nail Bed destruction + longitudinal splintering
What is the most concerning variant type of Lichen Planus that we need to consider DDx for?
Papular
lichen planus papular
For cutaneous lesions of Lichen Planus, the preferred tx is…
Triamcinolone under occlusion BID x 4 weeks
Can also use ILK
For Lichen Planus in the mouth, the preferred tx is…
Cyclosporine and Tacrolimus MOUTHWASH
LP and CT of th mouth
Systemic tx of Lichen Planus can use 3 drugs and 1 therapy, which are…
Cyclosporine
Prednisone
Retinoids (adjunctive)
PUVA therapy
What is the underlying pathophysiology of SJS & TEN?
Cytotoxic event destroying keratinocytes
what is the shape of a SJS TEN rash?
Target lesions with rapid confluence
When do you want to give to IV steroids and IVIG for SJS/TEN?
ASAP
