Dermatology for the Internist
Lecture by Dr. Sarah Wolfe. Summarized by Dr. Eric Wei
Epic Tricks
- General Dermatology Order Sets!
- Type in “Gen Derm” into the order section and numerous order sets will come up to treat common conditions including acne, atopic dermatitis, urticaria, hidradenitis, psoriasis. This is a great place to start as it highlights first, second, and third line treatment options
The language of dermatology
Primary features:
- Macule: flat, < 1cm
- Papule: elevation of any type, < 1 cm
- Patch: flat, > 1 cm
- Plaque: elevated, > 1cm
- Nodule: like plague but dome shaped
Secondary features:
- Crust
- Hemorrhagic Crust (aka scab)
- Yellowing of the crust–> suggests superficial infection with staph/strep
- Scale
- Fissure
- Lichenification
- Erosion
- Ulceration
Color
- Erythematous, white, purple, brown, yellow, black, etc.
Distribution
- Examples:
- atopic dermatitis commonly distributed where shoe rubs feet
- candida likes pannus, chest, moist areas
- Psoriasis – interdigital and plantar surfaces of the toes; well-demarcated plague with a thick silvery scale
Please see the Stanford 25 website which has an excellent introduction to the language of dermatology with great photos and videos: https://stanfordmedicine25.stanford.edu/the25/dermatology.html
Tinea Pedis (Athlete’s Foot) & other Tinea conditions (corporis, cruris, etc.)
- Clinical Patterns:
- Interdigital – flaking epidermis between toes
- Maceration can occur between the toes. Shows up first between the fourth and fifth toes.
- Moccasin – Forms a rim around the bottom of the foot
- Vesicobullous – blister forming
- Interdigital – flaking epidermis between toes
- Treatment
- First line:
- Clotrimazole cream BID x 4 weeks (can buy OTC as Lotrimin)
- Terbinafine Cream (e.g. Lamasil)
- First line:
- Things to avoid!
- Do not treat something that may be fungal with a topical steroid –> this will cause the rash to increase in size. If you are unsure if it is inflammatory or fungal, opt to treat for 4 weeks with OTC anti-fungals and instruct patient to use a topical steroid if this first line therapy is ineffective
Onychomycosis

- Key findings: subungual debris and nail discoloration
- What tests should be ordered?
- Fungal culture of subungual debris (textbook answer, although this is not always done clinically)
- Treatment
- First line: Oral terbinafine x 3 months
- After treatment, the nail will take roughly 1 year to “grow out” before it may return to normal.
- Treatment failure rate: 50%
- Terbinafine risks: low risk of hepatotoxicity; check baseline LFTs
- Ciclopirox nail lacquer
- This is a toenail polish. Must be used daily for 1 year. Treatment success rate is only 11%
- Second Line
- Itraconazole
- Pulse dosing for 3 months: 200mg BID x 7 days during the first week of every month.
- You must watch out for interactions with other medications: e.g. statins
- Fluconazole
- If there is concern for co-infection with mold, it can be useful
- First line: Oral terbinafine x 3 months
Tinea versicolor (pityrosporum yeast)
- May be hypo or hyperpigmented
- Treatment:
- Ketoconazole shampoo – 5 days
- Selenium sulfide (Selsun Blue)
Stasis dermatitis

- rash that results from 3rd spaced fluid; due to hemosiderin spilled from RBCs
-
- Tx: Triamcinolone; avoid skin, face, groin, armpits
- Compression wraps “unna boot” -> transition to compression stockings (20-30 mmHg)
Candida
- Candida will involve scrotum; dermatophytes usually doesn’t involve scrotum.
- Treatment: clotrimazole, nystatin, ketoconazole (not great for dermatophytes)