Dermatology List of Most Commons for Physician Assistant Students

Most PA programs teach in a systems-based style of learning with “block” style approaches to navigating through the mounds of medical factoids we must learn and know. It’s often talked about how PA students should start their own lists of “most commons” in medicine for each block or system in preparation for course examinations and the PANCE. It has come to my attention that this is most definitely the case. As such, I’ve decided to create a list of most commons for each block we cover, the first being Dermatology!

Most Commons in Dermatology:

1. Most common treatment for keloids: triamcinolone acetonide (corticosteroid) in concentrations of 10-40 mg/mL at 4-6 week intervals
2. Most common cutaneous cyst: epidermal inclusion cyst (EIC), also known as cutaneous cysts
3. One of Top 3 Skin problems in children: verruca vulgaris
1. Most common primary treatment: cryotherapy and salicylic acid (cure rate improved by combining both therapies)
4. Human Papilloma Virus (HPV) is one of the most common STIs causing Condylomata Acuminate, also known as External Genital Warts (EGW)
5. Most common type of psoriasis: Plaque Psoriasis (affects 80-90% of patients).
6. Most common clinical pattern seen in Psoriatic Arthritis:
1. Oligoarthritis - swelling and tenosynovitis of one/few hand joints.
7. The “Butterfly Rash”
1. Many facial rashes are described as malar or “butterfly” rashes
2. Most commonly, they are either: seborrheic dermatitis or rosacea, NOT systemic lupus erythematosus (SLE)
8. Most common dermatologic condition in infants: Diaper Rash (diaper candidiasis)
9. Tinea Capitis is most commonly caused by Trichophyton tonsurans (human to human or fomite to human transmission) in the US
1. Most common in school aged children (4-14) in US
2. Most common worldwide pathogen: Microsporum canis (animal to human)
10. Most common fungal infection in developed countries: tinea pedis (athlete’s foot)
11. Most common type of Onychomycosis: Distal Subungual Onychomycosis (DSO)
12. Most common skin cancer: basal cell carcinoma
1. Most common subtype: nodular
13. Most common form of ichthyosis: ichthyosis vulgaris
14. Most common variation of albinism: oculocutaneous albinism (autosomal recessive)
1. Second most common: ocular albinism
15. Most common sex chromosome disorder: Klinefelter Syndrome (x-linked recessive)
16. Most common subtype of melanoma: Superficial Spreading Type
17. Most common drug eruption: Exanthematous

Extras:

1. The “Dimple Sign” - often exhibited by dermatofibromas. Pinch on either side and observe a dimple due to scar-like tethering of the dermis.
2. The “Auspitz Sign” - bleeding after removal of scale. Exhibited by Plaque Psoriasis.
3. Pruritic Lesions
1. Keloid Scars
2. Psoriasis
3. Atopic Dermatitis
4. Allergic Contact Dermatitis
5. Tinea Corporis
6. Candida Intertrigo
7. Pityriasis Rosea
8. Nummular Dermatitis
9. Squamous Cell Carcinoma (sometimes)
4. Koebnerizing Lesions (Koebner phenomenon) - linear mode; spreads with trauma or scratching
1. Molluscum Contagiosum (MC)
2. Verruca Vulgaris
3. Plaque Psoriasis
5. Systemic Lupus Erythematosus - “mimics rosacea”
6. Atopic Dermatitis - the “itch that rashes”
1. The “itch” is the primary symptom and precedes onset
2. Also seen in Allergic Contact Dermatitis
7. Red Rashes
1. Greasy scale and redness
1. Seborrheic dermatitis
2. Tender Papules
1. Acne vulgaris, rosacea
3. Worse with exercise, heat, hot foods, alcohol
1. Rosacea
4. Eyebrows, nasal creases, external auditory canals
1. Seborrheic dermatitis
5. Cheeks and chin
1. Acne vulgaris, acne rosacea, atopic dermatitis
6. Nose
1. Acne vulgaris, acne rosacea
2. Spared in atopic dermatitis
7. Know Location, History, and Age to help differentiate red rashes on the face
8. When to run a KOH test
1. “All that scales, must be scraped”
2. First step in diagnosing a scaling annular rash on the body is to perform a KOH exam to rule out fungus
9. Tinea Versicolor
1. KOH Prep reveals “Spaghetti and Meatballs” pattern
1. Short hyphae and small round spores
10. Allylamines are NOT effective for Candida species
1. Nystatin ONLY works for Candida, not dermatophytes

Credits:

American Academy of Dermatology

UT Southwestern PA Program