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Flashcards in Derm Deck (50)
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1
Q

What is an epidermal inclusion cyst/epidermal cyst?

A

A benign nodule lined with squamous epithelium that contains a semisolid core of keratin and lipid.
Common on scalp, face, neck, or trunk
Presentation: dome-shaped, firm, freely movable cyst or nodule with a small central punctum (small dilated, pore-like opening); lesion can remain stable or gradually increase in size, but may produce a cheesy white discharge
Tx: it usually resolves spontaneously

2
Q

What is basal cell carcinoma?

A
#1 - The most common type of skin cancer
Presentation: pearly fleshy papule or plaque with small telangiectasias on sun-exposed areas (head and neck); persistent open sore that bleeds, oozes, or crusts; reddish patch or irritated area (superficial BCC), elevated or rolled border w/ central ulceration; pale scar like area w/ poorly defined borders
Biopsy - invasive cluster of spindle cells surrounded by palisaded basal cells 
Tx: Mohs micrographic surgery for the delicate or cosmetically sensitive areas (eg perioral region, nose, lips, and ears)
3
Q

What is squamous cell carcinoma?

A

2- Second most common skin cancer, primarily on sun-exposed areas

Most common malignancy of the lip, most common in IC pts or hx of organ transplant on chronic immunosuppressive therapy
RF: UV, ionizing radiation, immunosuppression, chronic scars/wounds/burn injuries
Presentation: lesions are usually firm and scaly papules, plaques, or nodules; +/- hyperkeratosis or ulceration, neurologic signs w/ perineural invasion, lip - indurated, ulcerating lower lip lesion
SCC arising w/in a scar or chronic wound carries increased risk of metastasis
SCC arising w/in a burn wound is known as a Marjolin ulcer
Dx: biopsy - dysplastic/anaplastic keratinocytes; invasive cords of squamous cells w/ keratin pearls
Tx: curative resection, lesions do not metastasize

4
Q

What is dermatofibroma?

A

A benign fibroblast proliferation
Presentation: firm, hyperpigmented nodule, most often on lower extremities
Have a fibrous component that causes dimpling in the center when the area is pinched (“dimple” or “buttonhole” sign)

5
Q

What is a lipoma?

A

A benign, painless subcutaneous mass with normal overlying epidermis.
Usually soft to rubbery and irregular, do not regress and recur

6
Q

What is melanoma?

A

Clinical features: Asymmetry - when bisected, 2 sides are not identical; Border irregularities - uneven edges, pigment fading off; Color variegation - variable mixtures of brown, tan, black and red; Diameter - >/=6mm; Evolving - lesion changing in size, shape, or color, new lesion
Concerns for malignancy - “ugly duckling” sign: lesion w/ appearance substantially different from the others; palpable nodularity; itching or bleeding
Breslow depth = most important prognostic indicator in malignant melanoma
Dx: excisional biopsy w/ initial margins of 1-3mm of normal tissue

7
Q

What is angiosarcoma?

A

A rare malignant tumor derived from the internal lining of blood vessels or lymphatic vessels
RF: pts who received localized radiation therapy for cancer treatment; breast cancer survivors with chronic lymphedema
Presentation: multiple ecchymoses or purpuric mass on skin of breast, axilla, or upper arm 4-8y following completion of breast cancer therapy
Dx: biopsy
Tx: surgical resection possibly curative

8
Q

What is pyoderma gangrenosum?

A

Epi: peak onset age 40-60, women>men, assoc. with inflammatory bowel disease, inflammatory (eg rheumatoid) arthritis, malignancy (eg acute myeloid leukemia)
Presentation: begins w/ small papule or pustule, rapidly progressive, painful ulcer w/ purulent base and violaceous border; precipitation of ulceration at site of injury (pathergy)
Dx: skin biopsy of ulcer margin (mixed cellular neutrophilic infiltrate w/ dermal and epidermal necrosis), exclusion of other causes of ulceration (eg infection)
Tx: local or systemic glucocorticoids

9
Q

What is superficial wound dehiscence?

A

A separation of the skin and subcutaneous tissue w/ an intact rectus fascia; results in scant serosanguinous fluid drainage
Tx: regular dressing changes

10
Q

What is deep (fascial) wound dehiscence?

A

Involves the rectus fascia (ie., nonintact); results in exposure of intraabdominal organs to external environment
Tx: surgery due to risk of bowel evisceration and strangulation

11
Q

What is bullous pemphigoid?

A

Autoimmune disorder
Common in pts >65yo, in those w/ malignancy or neurological disorders (Parkinson’s, MS)
Etiology: IgG autoantibodies against hemidesmosome and basement membrane zone
Presentation: severe pruritus, tense bullae on erythematous base; pre-bullous syndrome presenting w/ urticarial or eczematous lesions is common
Mucosal lesions are RARE.
Dx: skin biopsy
Microscopy: linear IgG + C3 deposits along basement membrane
Tx: high potency topical glucocorticoid (eg clobetasol)

12
Q

Dermatitis herpetiformis

A

Represents autoimmune dermal reaction due to dietary gluten; assoc. w/ celiac disease
Grouped pruritic vesicles on buttocks and extensor surfaces of the limbs
Biopsy: microabscesses at the tips of dermal papillae w/ deposits of IgA antibodies against epidermal transglutaminase in the dermis
Tx: oral dapsone + elimination of dietary gluten

13
Q

What is drug induced acne?

A

Assoc. w/ systemic glucocorticoids
Monomorphic papules w/o assoc. comedones, commonly involves the upper back, shoulders, and upper arms
Tx: discontinuation of offending agent

14
Q

What is mupirocin?

A

A topical antibiotic used to treat superficial skin infection such as impetigo, which presents w/ small vesicles w/ a yellow exudate and honey-colored crust.
It is also used to eradicate MRSA colonization from the nares.

15
Q

What is leukocytoclastic vasculitis?

A

Due to infections, meds, inflammatory conditions, or malignancy.
Presentation: non-blanching, 1-3mm violaceous papules that can cluster/coalesce into plaques.
Older lesions appear brownish-red; newer ones are more violaceous.

16
Q

Shave biopsy.

A

Not recommended for most cases of suspected melanoma as partial removal of primary melanoma may not provide adequate tissue for dx and does not allow for accurate depth measurement.

17
Q

What is irritant contact dermatitis?

A

Nonimmunologically mediated, can resemble allergic contact dermatitis w/ pruritis, erythema, local swelling, and vesicles
Sxs develop acutely (w/in h of exposure) but are often chronic leading to excoriation, hyperkeratosis, and fissuring of skin
Emollients and use of protective barriers can relieve sxs
Dx: based on clinical findings

18
Q

What is tinea manuum?

A

A superfical fungal infection of the hands
Typically presents as pruritic, hyperkeratotic patches on the palms or annular erythematous lesions resembling tinea corporis on the dorsum of the hands and finger webs.
Most pts have concurrent tinea pedis.

19
Q

What is urticaria?

A

Welts or wheals

20
Q

SLE rash

A

Spares the nasolabial folds

21
Q

Telogen effluvium

A

Hair pull test: extraction of >10-15% of fibers is abnormal and suggests TE
Self limited disorder that may take up to a year to resolve completely

22
Q

What is alopecia areata?

A

Autoimmune disorder characterized by circumscribed patches of hair loss.
Hair shafts show narrowing close to the surface and may be broken off.

23
Q

What is androgenic alopecia?

A

Causes uneven hair loss in a characteristic pattern.
Men have thinning at the frontotemporal hairline and vertix.
Women predominantly have thinning at the vertex and sides w/ preservation of the hairline.

24
Q

What is trichorrhexis nodosa?

A

Characterized by fragility of hair w/ breaking strands.
It can be congenital or acquired (eg excessive heat, hair dyes, salt water).
Close inspection shows fractured strands w/ splitting fibers.

25
Q

Phases of hair follicles.

A
Growth phase (anagen: 90% of follicles)
Transformative phase (catagen: <1%)
Rest/shedding phase (telogen: 10%)
26
Q

What is erythema multiforme?

A

Cell-mediated inflammatory disorder of the skin characterized by erythematous papules and plaques that evolve into target lesions.
Most commonly assoc. w/ HSV.
Biopsy: perivascular lymphocytic infiltrate and epidermal necrosis

27
Q

What is pemphigus vulgaris?

A

Painful, flaccid bullae, mucosal erosions

28
Q

What is bullous impetigo?

A

A blistering condition caused by s. aureus

Lesions appear as macules, vesicles, bullae and honey colored crusts which leave red denuded areas when removed

29
Q

What is pyoderma gangrenosum?

A

Rare neutrophilic dermatosis most often seen in pts w/ inflammatory bowel disease and arthropathies.
Lesions develop rapidly and begin as a cutaneous papule or nodule that quickly matures into a painful, purulent ulcer w/ violaceous borders.
Fever is UNCOMMON.

30
Q

Whatis pityriasis rosea?

A

Classically begins w/ a herald patch, an erythematous annular lesion on the trunk.
In a week, clusters of smaller, erythematous oval lesions appear on the trunk, distributed obliquely along the lines of tension in a “christmas tree” pattern most noticeable on the back.
May be assoc. w/ mild pruritus.

31
Q

What is tinea corporis?

A

Often occurs in athletes who have direct skin contact (wrestlers), presents w/ an erythematous, scaly, pruritic patch.
Lesions typically have central clearing and raised borders.

32
Q

What is nummular eczema?

A

Chronic rash characterized by dry, erythematous, and intensely pruritic patches on the extremities.

33
Q

What is tinea versicolor?

A

Superficial nondermatophyte fungal skin infection caused by Malassezia species and characterized by salmon-colored, hyper- or hypopigmented macules that are sometimes covered by fine scales.
Hypopigmented areas are frequently noticed following sun exposure due to tanning of surrounding skin.
Dx: KOH preparation of skin scrapings
Tx: topical antigungals (ketoconazole, terbinafine, selenium sulfide)

34
Q

What is psoriasis?

A

Presents w/ chronic salmon colored erythematous plaques w/ a white or silver scale
Primarily located on the extensor surfaces (eg knees, elbows) and scalp
Initial tx for limited plaque psoriasis: topical high potency steroids (betamethasone, fluocinoide) or vitamin D derivatives (calcipotriene)
Moderate -severe: may require phototherapy or systemic treatment

35
Q

What is tinea corporis?

A

Characterized by ring-shaped scaly patches w/ central clearing and distinct border. May become confluent to form “flower petal” shape.
Extensive in pts w/ HIV, DM
Dx: KOH prep of skin scraping
Tx: Mild-moderate: topical fungals (terbinafine, clotrimazole)
Extensive: systemic therapy (oral terbinafine, fluconazole, itraconazole)

36
Q

What is eczema herpeticum?

A

A complication caused by a superimposed primary HSV1 infection; an open area is exposed to HSV1
A primary HSV infection associated w/ atopic dermatitis.
Painful vesicles, “punched out” erosions and hemorrhagic crusting along w/ fever, irritability, and lympadenopathy are typical.
May be lifethreatening in infants
Tx: systemic acyclovir

37
Q

What is seborrheic dermatitis?

A

Causes pruritic, erythematous plaques w/ greasy scale that predominantly affect the scalp (dandruff) and face (eyebrows, nasolabial folds, and external ear canal/posterior ear), chest, and intertriginoius areas.
It is most common in the 1st year of life and in midle age and can be assoc. w/ Parkinson disease and HIV.
Malassezia species may play a role in pathogenesis
Topical antifungal agents are effective treatment (ketoconazole, selenium sulfide)

38
Q

What is congenital melanotic nevus?

A

A benign proliferation of melanoctye cells.
Presents w/in first few months of life and usually solitary, hyperpigmented lesions w/ an increased density of overlying dark, coarse hairs
Risk of tranformation to melanoma increases (up to 5%) w/ increasing size and large lesions are often removed surgically to reduce risk.
Small lesions may be removed for cosmetic reasons given low risk of melanoma transformation.

39
Q

What is congenital dermal melanocytosis (Mongolian spots)?

A

Present as flat, gray-blue patches that are poorly circumscribed and will fade w/ time.
Classically located on the lower back and sacrum and more common in AA and Asians.

40
Q

What is lentigo?

A

Result of intraepidermal melanoctye hyperplasia.

Most common in older individuals and is characterized by a round or oval macule w/ even pigmentation.

41
Q

What is erythema nodosum?

A

A condition of painful, red or violaceous, subcutaneous nodules.
Can be a sign of more serious disease (strep infection, sarcoidosis, TB, endemic fungal disease, IBD, behcet disease)
Prevalence of sarcoidosis in pt w/ EN is as high as 28%
Even in absence of respiratory symptoms, CXR should be performed in pts w/ EN to assess for findings consistent w/ sarcoidosis.

42
Q

Contact dermatitis

A

Type 4 hypersensitivity; rash can appear days after exposure
Toxicodendron plants (poison ivy/oak/sumac) are a frequent cause of allergic contact dermatitis.
The erythematous, vesicular rash involves exposed skin and can form linear streaks where skin has brushed against the plant leaves.

43
Q

What is cavernous hemangioma?

A

Also known as cavernous malformation, consist of dilated vascular spaces w/ thin walled endothelial cells.
Present as soft blue, compressible masses growing up to a few cm
May appear on skin, mucosa, deep tissues, and viscera.
Cavernous hemangiomas of the brain and viscera are assoc. w/ von Hippel Lindau disease

44
Q

Cherry hemangioma

A

Small red cutaneous papules common in aging adults

They do not regress spontaneously but they are benign and generally do not require treatment

45
Q

Strawberry (infantile) hemangiomas

A

Appear during first weeks of life
Initially grow rapdily and then frequently regress spontaneously by ag 5-8
They are bright red when near the epidermis and more violaceous when deeper

46
Q

What is ichthyosis vulgaris?

A

A chronic, inherited skin disorder characterized by diffuse dermal scaling.
Caused by mutation in the filaggrin gene and worse in individuals who are homozygous.
Skin appears dry and rough w/ horny plates resembling fish or reptile scales.
Worsens in the winter due to decreased ambient humidity
Tx: emollients, keratolytics, and topical retinoids

47
Q

What is lichen planus?

A

Immunologically mediated skin disorder affecting middle age adults
Presents w/ pruritic, purple/pink, polygonal papules and plaques on flexural surfaces of the wrists and ankles.
Lesions may also occur on oral mucosa, nails, and genitalia.
Often show white, lacy markings known as Wickham striae and can form along lines of minor trauma (Kobner reaction)
Often assoc. w/ hep C.
Self-limited.
Tx: topical glucocorticoids

48
Q

What is tinea capitis?

A

Transmission through human to human contact or fomites (shared combs)
A superficial dermatophytosis that most commonly occurs in children and immunocompromised patients.
It causes a scaly, erythematous patch that can progress to alopecia w/ inflammation, pruritus, lymphadenopathy (occipital, postauricular), and scarring.
Oral griseofulvin or terbinafine are preferred

49
Q

What is senile purpura?

A

Usually presents w/ ecchymoses in elderly pts in areas exposed to repeated minor trauma (eg extensor surfaces of the hands and forearms).
Due to age-related loss of elastic fibers in perivascular connective tissue.
Not dangerous and requires no further evaluation.

50
Q

What is squamous cell carcinoma in situ of the skin (Bowen disease)?

A

> 60yo
Presents as a slowly enlarging, scaly, erythematous patch or plaque.
It most commonly occurs on sun-exposed skin and is usually not assoc. w/ pain or itching.
-often develops in regions w/ signs of solar damage (actinic keratosis, hyperpigmentation, telangiectasias)
-may also arise in areas w/ chronic inflammation, scarring, or previous infection w/ high risk HPV (perianal skin, genitalia)
B/c SCC in situ can develop foci of invasive SCC,
biopsy is recommended for confirmation.