Medical Student Guide

Dermatology Elective

MSSM

Primary Lesions

Psoriasis

Bullous Disease

Acne

Eczema

Infectious (Fungal, Bacterial, Viral, Pest)

Malignancy

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High-Yield Knowledge

Primary Lesions

Plaque:

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Patch:

Papule:

Macule:

Vesicle:

Ulcer:

Bulla:

Erosion:

<1cm, elevated

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>1cm, elevated,

if depressed 🡪

Depressed plaques

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Pinpoint purpura

<1cm, fluid-filled

papule, superficial,

Thin-walled,

Intraepidermal

Epidermis and

Dermis or deeper,

Heals with scar

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>1cm, Fluid-filled

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Epidermis only,

Heals without a

scar

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<1cm, flat

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>1cm

non-elevated

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Nodule:

Elevated, round

and deeper than

a papule

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Pustule:

Pus filled papule or vesicle

>1cm non-blanching

Red-purple

patches

Ecchymosis

Purpura

Petechia

<1cm non-blanching

Red-purple

macules

Telangiectasis:

Small dialated blood vessels

Evanescent

Papule or

plaque

Fissure:

Wheal:

Burrow:

Linear Papule

= scabies

Linear cleft

Secondary Characteristics

-Color

-Scale

-Border

COLOR:

-Brown/black – from melanin or coagulated blood

-Blue – from melanin in dermis or venous blood

-White – absence of melanin

-Erythematous (red) – from dilated capillaries

-Violaceous – vascular or dense cellular infiltrate

-Yellow – from lipid deposition or jaundice

-Green – Pseudomonas superinfection (pyocyanin)

-Orange - Carotenemia

SCALE:

-Flaking of top layer of epidermis, usually due

to higher than normal turnover

-Characterized histologically by parkeratosis

-Types of scale:

• Fine
• Silvery
• Collarette of scale

BORDER:

-Rolled (e.g., basal cell carcinoma)

-Sharply demarcated (e.g., psoriasis)

-Notched (e.g., melanoma)

-Scalloped (e.g., herpes)

Distribution:

-Crop (e.g., herpes)

-Satellite lesions (e.g., candida)

-Dermatomal (e.g., zoster)

-Generalized (+/- but spares…) (e.g., drug rash, psoriasis)

Psoriasis

Classifications:

Plaque psoriasis

Guttate psoriasis

Pustular psoriasis

Inverse psoriasis

Palmoplantar psoriasis

Erythrodermic psoriasis

Nail psoriasis

Psoriatic arthritis

Description:

Well-demarcated, red plaques with silver scale

Treatment:

Protopic/Elidel – face & groin

Topical Steroids – to body

Cyclosporine

Methotrexate

Phototherapy

Dovonex

Soriatane

Enbrel, Humira, Remicade, Stelara

Pathophysiology: Th1 mediated;

INF; TNF; IL 12/23

Mild-to-moderate psoriasis (topicals):

• Steroid
• Vitamin D analogue
• Retinoid
• Calcineurin inhibitor

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Moderate-to-severe psoriasis (systemic):

• MTX, CsA, oral retinoids, phototherapy or biological agents (adalimumab, etanercept, infliximab, golimumab, ustekinumab) are often prescribed in conjunction with topical therapy.
• Review article on use of biologics: http://dermatology.cdlib.org/1802/02_rev/02_11-00245/article.html

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Psoriatic Arthritis:

• Treat early to avoid further structural damage.
• Mild disease – NSAIDs
• Severe disease - biological agent +/-MTX

Oral steroids cause flare upon discontinuation = contraindicated!!

Bullous Disease

Pemphigus Vulgaris

Description:

• Flaccid bullae
• “Nikolsky’s sign”
• Oral erosion frequent

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Pathophysiology:

Antibodies against

Desmosome: Desmoglein 3

Bullous Pemphigoid

Description:

• Tense blister
• Roofed at presentation
• Not mucous membranes

Pathophysiology:

Antibodies against Hemi-desmosome: Bullous

pemphigoid antigen 1 or 2 (Collagen XVII)

Treatment for Both:

• Prednisone (40-80mg/day) with gradual taper
• Cellcept/Azothioprine
• Rituxan
• IVIG

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Bullous Pemphigoid specific:

• Hydroxyzine 10-50mg Q4 hr for itch
• Clobetasol BID to lesions
• Tetracycline 500mg qid + Niacinamide 750mg bid

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Acne

Description:

• Red papules and pustules
• Open/Closed comedones
• Cysts

Wait 3-6 weeks before expecting any improvement

Treatment:

• Topical Retinoids
• Tazarotene 0.1% cream
• Adapalene 0.1% or 0.3% +/- benzoyl peroxide (BPO)
• Acne surgery: nick with 11 blade 🡪 comedone extraction
• Topical Antibiotics
• Benzoyl peroxide 5-10%
• Clindamycin 1%/BPO 5%
• Doxycycline 100mg PO BID
• Spironolactone 25-50mg bid (for PCOS)
• Accutane (1mg/kg)
• Check TG, β-hCG, ALT, AST

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Dr. Levitt’s way:

• Everyone: triclosan or salicylic acid bar soap

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• Papules/Pustules: BPO/clinda (Duac gel) BID x 6 weeks then tazarotene 0.1% (Tazorac) short contact

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• Comedones: acne surgery +/- tazarotene 0.1% cream – leave on x2 min, increase by 30 sec q4d

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• Cysts: endocrine work-up; doxycycline 100mg PO BID or isotretinoin or spironolactone

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Comedonal acne

Papulopustular acne

Nodulocystic acne

Acne keloidalis nuchae

Eczema/Atopic Dermatitis

Description: Lichenified, Oozing/Weeping, Excoriated, Plaque

Treatment:

• Face/groin:
• Mid potent steroid - acutely
• Protopic/Elidel – chronically
• Body:
• Clobetasol or Topicort 0.25% ointment BID 2wks, then weekends only
• Severe:
• Intramuscular TAC 30mg to each buttock
• Prednisone 60mg QDx3D, taper by 10mg Q2D, #48, NO refills
• Phototherapy
• Cyclosporine
• Cellcept
• MTX
• Antibiotic for associated impetigo

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Differential:

• Seborrheic dermatitis
• Allergic contact dermatitis
• Psoriasis
• Mycosis fungoides

Nummular eczema

“coin-shaped"

Atopic eczema

Dyshidrotic eczema

Dennie-Morgan lines

Eczema Herpeticum

Fungal Infections

Tinea Pedis

Description: Toe webs with scales, red patches

Etiology: T. rubrum

Test: KOH+

Onychomycosis

Description: Subungual hyperkeratosis. Thickened, discolored nails

Test before oral Lamisil: SMA 20, CBC, nail clipping to path

Description: Usually annular, sometimes vesicular, erythematous scaly plaque

Etiology: Trichophyton rubrum (most common)

Test: KOH +

Tinea corporis

Treatment:

• Localized: Terbinafine cream
• General Body: Lamisil 250mg PO QD x 2wk
• 1 hand – 2 feet/Beard/Hair: Lamisil 250mg PO QD x 6wk
• Nails: Lamisil 250mg PO QD x 12wk

Positive KOH

Bacterial Infections

Impetigo

Description: Honey-colored crust, often with eczema. Bacteria introduced by scratching.

Etiology: Group A β-hemolytic Strep or Staph aureus (rule out MRSA)

Test: swab culture

Treatment: Keflex 500mg 4x/day (adult). Mupirocin ointment topically TID.

Furuncles

“boil”

Description: erythematous follicular-based nodule or pustule

Etiology: Group A β-hemolytic Strep or Staph aureus (rule out MRSA)

Diagnosis: Clinical diagnosis – should culture at initial visit.

Treatment: I&D, Cx, warm soak, Bactroban, +/- oral abx

Cellulitis

Description: Erythematous, edematous, warm, tender plaque

Etiology: Group A β-hemolytic Strep or Staph aureus (rule out MRSA)

Diagnosis: Clinical diagnosis (3/4 or 4/4 of erythema, edema, warmth, tenderness)

Treatment: If MRSA+: Vanco IV ; If NOT MRSA: Levaquin or Augmentin

Viral Infections

Herpes Zoster

“Singles”

Description: Grouped vesicles on an erythematous base in a dermatomal

distribution.

Etiology: Reactivation of latent VZV in the sensory ganglia

Diagnosis: Clinical diagnosis; confirm with DFA, Tzank smear or viral culture.

Treatment: Valtrex 1g PO TID x 7d

Description: Grouped vesicles on an erythematous base

Etiology: HSV type 1 or 2

Diagnosis: Clinical history of recurrent blisters or erosions in the same site.

Confirm with Tzank, DFA or viral culture.

Treatment: Oral: Valtrex 2g q12h x 2 doses. Others: Valtrex 1 g PO TID x 7d

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Herpes

Description: Hyperkeratotic verrucous papules

Etiology: HPV 1,2

Treatment: Cantharidin (blistering); Cryotherapy; paring; ED&C; pulsed dye laser; others

Verruca Vulgaris

“Common Wart”

Lice & Scabies Infections

Description: red papules with Burrows!!!

Symptoms: Itch

Treatment:

• Permethrin 5% cream once, repeat in 4d
• Ivermectin 200ug/kg, 1-2 doses separated by 3-7 days
• Clip fingernails
• Fomites to dryer @ 60^oC x 10min
• Treat contacts, who are often asymptomatic

Findings: immobile nits and live lice

Symptoms: Scalp pruritus or

asymptomatic!

Scabies burrows

Lice

Sarcoptes scabiei

Pediculus humanus

var. capitis

Treatment:

• Fomites to dryer @ 60^oC x 10min
• Malathion 0.5% once, repeat in 1 week
• +/- Tx contacts

Drug Hypersensitivity

Morbilliform

EM SJS TEN

Treatment:

• Drug chart
• D/C the drug
• Topical steroids
• Check LFTs, CBC w/ diff

LCV

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Treatment:

• DDx: Meds, HepB/C, cryoglobulinemia
• W/U: HepB/C, CBC w/ diff, Bx for H&E, DIF, cryoglobulins

Treatment:

• Drug chart
• D/C drug
• Check LFTs, CBC w/ diff
• IVIg vs. Cyclosporine vs. Prednisone

Malignancy

Squamous Cell Carcinoma

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Melanoma

Basal Cell Carcinoma

A: Asymmetry

B: Notched Border

C: Varied Color

D: >6mm diameter

E: Evolution

• Five-year survival is

based on the thickness

of the tumor

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4 subtypes of Melanoma:

1. Superficial Spreading

2. Nodular

3. Lentigo maligna

4. Acral lentiginous

1. Nodular:

• Pearly, shiny,

semitranslucent,

papule or nodule

• Rolled border
• Telangiectases
• Erosion or ulceration

2. Pigmented:

• Brownish to

blue-black

• Seen in more darkly

pigmented persons

3. Morpheaform:

• Whitish, atrophic,

scar-like plaque

• Surrounding

telangiectasia

Keratoacanthoma

• Low-grade SCC
• Arise quickly
• Can spontaneously

Regress

• Can attain diameter

of 1.0-2.5cm

1. Bowen's disease

• In situ SCC
• Keratinocytes lose polarity
• Increased mitotic rate

2. Erythroplasia of Queyrat

• In situ SCC on the penis
• Often HPV-related

3. SCC of Mucus Membranes

• Highest chance of metastasis

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Solar “Actinic” Keatosis

Pre-malignant

Can progress to SCC

• Treat: Cryotherapy, Aldara, Efudex, ingenol mebutate

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Biopsy!!

Needle & Syringe

Venipuncture

ILTAC/Injections

Suturing

Scraping/Paring

Acne Surgery

KOH Staining

Notes & Prescriptions

Commonly Prescribed Meds

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Procedures

Needle and Syringe

Venipuncture I: http://www.youtube.com/watch?v=EkvU56BPBtg

Venipuncture II: http://www.youtube.com/watch?v=EkvU56BPBtg

Venipuncture III: http://www.youtube.com/watch?v=Cc-3k6i_HEg

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Needle & Syringe I: http://www.youtube.com/watch?v=nlXdHsXR1rQ

Needle & Syringe II: http://www.youtube.com/watch?v=kp26pihMVmM

Intralesional Triamcinolone Acetonide

“ILTAC”

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• Use Leuer lock syringe for safety
• Shake the small glass 5mL bottles well before use.
• Use a 23 gauge needle to draw up, and switch to 30 gauge to inject.
• Have either eye protection or a glass slide as a shield

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Dilute TAC-40 with Bacteriostatic H₂O

Keloids: http://www.youtube.com/watch?v=rhVNFXVDt3A

IM: http://www.youtube.com/watch?v=mJic3QLxA54

Acne: http://www.youtube.com/watch?v=F4RfJJVNNZ4

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Suturing

Have Dr. Levitt show you in person how to suture correctly! (after watching video/reading manual)

Part I: http://www.youtube.com/watch?v=Oh15sIZN390

Part II: http://www.youtube.com/watch?v=ZRpkBVlgreI

Part III: http://www.youtube.com/watch?v=EuFLfuf_cc8

Part IV: http://www.youtube.com/watch?v=eFnH3yUN-vk

Simple Suture

3mm Punch Biopsy followed by suturing

2mm Punch Biopsy followed by Aluminum Chloride

Suture removal

Of course, unwrap instruments before putting on tray & NEVER keep stock bottle of AlCl₃ on the tray

Shave/Excision/Paring/C&D

Part I: http://www.youtube.com/watch?v=JPhHSnLEzhc

Part II: http://www.youtube.com/watch?v=Kezz4YA-gR8

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Shave Biopsy

Paring

Part I: http://www.youtube.com/watch?v=td_ZewNy43U

Part II: http://www.youtube.com/watch?v=2J0BhmU4OIU

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Excision

Part I: http://www.youtube.com/watch?v=374FdhuXvt8

Part II: http://www.youtube.com/watch?v=JEiRWtkQfNs

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Curettage and Desiccation (C&D)

*The cotton-tipped applicators should have AlCl₃ on them.

**Hyphercator with condom and correctly applied tip is missing in this picture

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Blade for Paring

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KOH Staining

KOH scraping: http://www.youtube.com/watch?v=hTJLHFoZM3s

Notes & Prescription Writing

• Methotrexate only comes in 2.5mg pills, so the above script is for a patient who needs to take 20mg/day. Dispense enough for 1 month, and no refills

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Confirm DOB with Pt.

Number each lesion with the description

& location

A/P: Numbers correspond to the numbered descriptions

Doctor’s Signature

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Follow-up

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Commonly prescribed meds

Antibiotics

Topical

• Clindamycin 1% solution / lotion BID
• Bactroban cream / oinment TID
• Triple Abx (for Pseudomonas)
• Metrogel

Oral

• Cipro 500mg po bid
• Augmentin 500mg po tid
• Keflex 500mg PO QID
• Levaquin 500mg PO q24h x7-10 days
• Doxycycline 100mg PO BID

Steroids

Topical

• Clobetasol cream / lotion BID x 2 weeks,

then weekends only (Class I),

avoid face and groin

• Fluocinolone 0.025% (Class IV)
• Topicort 0.25% cream / ointment (Class II)
• Topicort 0.05% LP cream (Class IV)
• Hydrocortisone 1% cream (Class VII)

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Pruritus

Topical

• Sarna lotion QID PRN
• Pramasone lotion 1% or 2.5%

Oral

• Doxepin 10-100mg QHS
• Atarax 10-50mg PO QHS
• Benadryl 25mg PO TID or QHS
• Loratadine up to 20mg BID
• Zyrtec up to 20mg BID
• Allegra up to 120mg BID

Acne

Topical

Tazorac 0.1% gel / cream,

apply to face x 2min, wash off.

Increase by 30 sec Q 4d (Disp: 100mg)

Duac gel BID

Differin cream

Epiduo

RetinA

Oral

Accutane, 1mg/kg (weigh patient)

Labs: CBC, SMA 20, Lipids, β-hCG

Doxycycline 100mg PO BID

Spironolactone 25-50mg po bid

Labs: BMP (for potassium)

Psoriasis Biologics

Enbrel 50mg sc biw or qweek

Humira 40mg sc eow

Remicade 5-10mg/kg q4-8 wks

Stelara 45-90mg q 3 months

Psoriasis/Eczema

Topical

• Steroids BID x2wks then weekends

only. Avoid face and groin.

• Protopic/Elidel to face and groin

Oral

• MTX (Labs: CBC, CMP)
• Cellcept (Labs: CBC, CMP)
• CysA (Labs: blood pressure, CBC, CMP, triglycerides, Mg, uric acid)
• Prednisone or IMTAC (eczema only)
• Soriatane 10mg or 25mg (Labs: CBC, CMP, Lipids, β-hCG)

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