Dermatology II scenarios

Question 1

Would a pt with a Fitzpatrick skin type of 1 burn frequently or infrequently?

Answer 1

Frequently

Question 2

An older pt has lots of small papules and larger plaques with a “stuck-on” appearance.

1) They likely have what?
2) Is this benign or malignant? Does it need Tx?
3) What should you exclude before you Dx this?

Answer 2

1) Seborrheic keratosis
2) Benign; no treatment necessary, can use cryo if bothersome
3) SCC & melanoma

Question 3

A pt with an endocrine disorder and obesity has velvet, thickened, hyperpigmentation on their neck, axilla, groin, and other body folds.

1) They likely have what?
2) Is this curable?

Answer 3

1) Acanthosis nigricans
2) Difficult to completely eradicate

Question 4

A 45 year old pt has a small, bright red papule on their trunk. They also have a dark purple/ blackish papule of a similar nature, also on their trunk.

1) What do they have?
2) Do you need to Tx? Explain

Answer 4

1) Cherry angiomas aka hemangiomas
2) Not needed; but, laser or electrocoagulation. Cryo not effective

Question 5

A farmer presents with multiple rough, scaley, pink lesions that are not well demarcated on his neck, his head, and hands. They feel like sandpaper.

1) This is describing what?
2) Is this benign or malignant? Does it need Tx?

Answer 5

1) Actinic keratosis
2) Precancerous (m/c precursor lesion of Squamous cell carcinoma)
-Cryo- and laser surgery, 5- fluorouracil cream, imiquimod cream

Question 6

A selfie-taking middle school girl has pruritis of her scalp and neck. Upon inspection there are excoriations on her scalp, and visible dots along her hair shafts.

1) What is the likely Dx?
2) DDxs?
3) How do you make the Dx?

Answer 6

1) Pediculosis (lice)
2) Seborrheic dermatitis, scabies, bed bugs, hair spray or gel, impetigo, LSC, delusions of parasitosis
3) Clinical detection of lice (louse comb), nits within 4 mm of scalp

Question 7

How would you treat a pt with pediculosis (lice)?

Answer 7

1) Over-the-counter treatment: Permethrin cream rinse (5% Elimite, 1% Nix) (resistance common)
2) Prescription treatments:
-Topical ivermectin lotion (most effective,) benzyl alcohol
-Malathion (Ovide): > 6 y/o (volatile, flammable)
-Lindane (Kwell): not 1st line (neurotoxicity, seizures), do not use in children. Not used in US
3) Other: Remove nits using a special comb (wet combing)
-Sanitize clothing and bedding (hot water)
-Examine/treat close contacts at same time, especially children

Question 8

A toddler pt has intense, generalized, intractable pruritis “itching so bad they can’t sleep”. Upon PE you note burrows, vesicles, nodules, excoriations and serpiginous ridges. It is all over their body and head, but predominantly in ridges/ skin folds.

1) What is the Dx?
2) How do you make this Dx?
3) Tx?

Answer 8

1) Scabies (Sarcoptes scabiei)
2) Clinical, skin scraping for mites, eggs, & feces
3) Elimite (5% Permethrin 60 gm) - apply from neck down after bath (< 2 yo treat head also) leave on 8-10 hrs then rinse. Repeat in 1 wk. Do not use in children < 2 months old
-Ivermectin 0.2 mg/kg/dose PO q2wk x 2 doses give w food if crusted or severe give more often
-Pruritis can continue up to 2-3 weeks (Post Scabietic Dermatitis); can use topical steroids, antihistamines (Atarax, Benadryl)
-Clothes, sheets, etc. wash normally the next morning; bedspread, stuffed animals, pillows, coats put in plastic bag for 7 days
-Treat all family members on the same nights as patient

Question 9

A pt says they were bit by a spider on their hand while grabbing firewood. They report that they initially had no Sx, but around an hour and a half later, they began to experience muscle pain.

1) Dx?
2) Tx?
3) When can they expect the pain to go away?

Answer 9

1) Black widow bite (Latrodectus (widow spiders))
2) Depends on severity, but consider antivenom + monitor vitals and breathing closely
3) Pain self-limited, resolves in 24-72 hours

Question 10

A pt has red, white, blue lesion on their upper arm with some necrosis.

1) Dx?
2) Important pt of Tx?

Answer 10

1) Brown recluse bite (Loxosceles (recluse spiders))
2) Surgical debridement

Question 11

A pt has a scarring type of alopecia. Can they expect their hair loss to be temporary or permanent?

Answer 11

Permanent

Question 12

A pt with Hashimoto thyroiditis has a round patch on their scalp of “exclamation point hairs” (2-3 mm long) with no visible scarring. They also seem to be missing a patch from their beard.

1) What could this be? What can this be associated with?
2) Does it need Tx? Explain

Answer 12

1) Alopecia areata
2) Self-limiting: 80% complete re-growth (focal)
PO steroids (severe), IL steroids

Question 13

A 55 year old female just lost a bunch of weight a year ago. She got COVID shortly after. She got a divorce this year. She is now experiencing hair loss.

1) Likely Dx?
2) How do you Dx?
4) Tx?

Answer 13

1) Telogen Effluvium
2) Pt. history + hair pull test (if > 4-6 hairs fall out w bulbs @ root then TE likely) + labs (thyroid panel, vitamin deficiencies)
4) Supportive care, reassurance, self-care.
-Hair grows back over months when stress resolves

Question 14

A pt with DM has subungual debris w. friable nails.

1) Likely Dx?
2) How would you need to confirm this Dx?
3) Should you Tx?

Answer 14

1) Tinea unguium (trichophyton (T. rubrum) infection)
2) KOH prep (hyphae), fungal culture
3) Difficult to treat: long therapy & frequent recurrence, but you should treat this pt
Indications for treatment: discomfort, inability to exercise, DM, immunocompromised

Question 15

1) How would you Tx a pt with Tinea unguium who has an indication to treat?
2) What do you need to do before you treat?

Answer 15

1) Fingernails: PO griseofulvin w/high fat meal x 4mo
Toenails: PO terbinafine
2) Must confirm dx prior to tx **Hepatic function test & CBC q4-6 weeks for PO antifungals

Question 16

Karen has DM and gets manicures often. She presents w. sudden redness, pain, and pus coming from the base of her fingernail.

1) Likely Dx?
2) Tx?

Answer 16

1) Paronychia
2) I&D abscess (since her case is acute)

Question 17

1) A pt might present with dermatophytosis (tinea ______) if they do what?
2) What do you need to remember to do when treating any dermatophytosis?

Answer 17

1) Constantly create a moist environment on their body
2) Monitor LFTs and CBC/ANC

Question 18

A pt says they’ve had “jock itch” before. You know this means?

Answer 18

Tinea cruris (tinea of crural fold, groin)

Question 19

A pt says they’ve had “ringworm”. This means?

Answer 19

Tinea corporis (tinea of body, extremities)

Question 20

A pt has a circular lesion on their torso with erythematous border and scales, and with excoriation or vesicles. They say it’s itchy.

1) What is it?
2) How would you Dx?
3) Tx?

Answer 20

1) Tinea corporis (tinea of body/ extremities)
2) Skin scraping, KOH prep
3) Topical antifungal (clotrimazole cream OTC = Lotrimin. PO antifungal if widespread or resistant to topical treatment.

Question 21

A pt has hypo/hyperpigmentation with sharp margins scattered all over their trunk. It is flat and slightly scaly.

You suspect tinea versicolor.
1) So you do a skin scraping and expect to see what?
2) What would you expect to see on a woods lamp?

Answer 21

1) Round yeast and elongated hyphae = “spaghetti and meatballs”
2) Fluoresce blue/green

Question 22

A sexually active pt has soft flesh -colored papules that are “cauliflower -like” on their genitals and perineum.

1) You suspect what?
2) What is the etiology of this?
3) Tx?

Answer 22

1) Condyloma acuminatum (HPV)
2) HPV 6 and/or 11 most common
3) Cryotherapy, Imiquimod 5% cream, surgery

Question 23

A pt has a few dome-shaped, waxy papules 2-5 mm diam that are umbilicated. They’re on their lower abdomen and genitals.

1) Potential Dx?
2) Etiology of this Dx?
3) Best Tx?

Answer 23

1) Molluscum contagiosum
2) Poxvirus
3) Curettage or liquid nitrogen (cryotherapy)

Question 24

A pt has a few burning, stinging, grouped vesicles on erythematous base (“dew drops on a rose petal”) on their lips. They said they’ve had this before, but it went away after their doctor treated it, and came back after their beach vacation.

1) Likely Dx?
2) Tx options?

Answer 24

1) HSV-1 (oral)/ herpes simplex
2) Mild recurrences: (this case) no therapy for most, may use 3-5 days of antivirals (above)
Frequent or severe recurrences: suppressive antiviral therapy reduces outbreaks & viral shedding (labialis – valacyclovir 500 mg PO QD, genital 1000mg PO QD)

Question 25

A sexually active pt has burning, stinging, grouped vesicles on an erythematous base. They also report regional lymphadenopathy.

1) Dx?
2) DDxs?
3) Tx?

Answer 25

1) Herpes simplex (either HSV-1 or HSV-2)
2) Chancroid, syphilis, trauma, other vesicular skin eruptions
3) 1st episode: acyclovir 400 mg PO TID x 7-10 d (or BID for suppression,) valacyclovir, or famciclovir

Question 26

A pt being vaccinated had a 98% chance of preventing what skin condition that has a unilateral dermatomal pattern?

Answer 26

Varicella zoster virus (VZV)

Question 27

1) VZV is dormant where in your pt’s body after a primary infection?
2) What can this cause them to present with?

Answer 27

1) Cranial nerve sensory ganglia & spinal dorsal root ganglia after primary infection
2) VZV/HHV-3 herpes zoster (shingles)

Question 28

A pt may present with pain without a rash (before the rash develops) with what condition?

Answer 28

Varicella zoster virus (VZV)

Question 29

An obese pt with DM taking steroids has itchy and erythematous digital, inframammary, and inguinal papules and patches that have become macerated; they’re often images with satellite lesions.

1) Dx?
2) Tx options?

Answer 29

1) Cutaneous candidiasis
2) Keep area dry, nystatin cream; PO antifungals if severe

Question 30

A pt experiences pain or changes in taste. These are Sx of what easily treatable condition?

Answer 30

Oral candidiasis (Tx = nystatin susp: swish and spit QID x 1wk)

Question 31

What is the primary Tx for your pts with warts (HSV)?

Answer 31

Oculoplastic surgery