Plaques and Scaly Skin Lesions

Question 1

Candidiasis

Answer 1

Superficial yeast infection occurring on moist cutaneous sites, usually caused by Candida albicans

1. intertrigenous areas
2. infra-mammary, infra-abdominal
3. inguinal groin
4. axilla
5. Mouth/tongue
6. Nail infection

Secondary manifestations:

Candida intertrigo, balantitis, thrush, chronic paronychia

Age: infants (diaper, mouth), adults (infra-mammary and infra-abdominal, inguinal groin and mucosa)

Sex: both

Predisposing factors: obesity, diabetes, immunosuppression, heat, hyperhidrosis, maceration, chronic debilitation, increased antibiotic use

Question 2

Seborrheic dermatitis

Answer 2

—Caused by yeast – malassezia furfur

• Yeast munches on oil – secretes irritated, inflammatory substances on the skin – skin responds by scaling/flaking to remove the insult.
• Occurs in areas that have a lot of sebaceous glands: Scalp, ears, face, central chest and intertrigenous areas

-Chronic

DDX: rosacea, ACLE, inverse psoriasis, candidiasis, SCLE, eruptive psoriasis

Question 3

Fungal Skin Infections

(superficial mycoses)

Answer 3

• Caused by fungus (form spores)
• Can infect any keratinaceous surface (skin, hair and nails)
• Trichophyton
• Microsporum
• Epidermophyton

Called “Tinea” infections

—Age – all ages

—Sex – M>F

—Predisposing factors: similar to C. albicans – atopy, steroid use, immunosuppression, humidy, sweating, occlusion, skin surface disruption

Recurring infections due to spores

-consider prophylatic treatment

Question 4

Tinea Infections

Answer 4

-Named based on location

Body – tinea corporis / “Ring worm”

Feet – tinea pedis

Groin – tinea cruris

Hand – tinea mannum

Scalp – tinea capitus

-Lesions are centrifugal –> Center is olderst part, biopsy obtained from the edges

Question 5

Keratinases

Answer 5

• Digest Keratin
• Associated with fungal skin infections

Question 6

Kerion

Answer 6

• Wet, purulent, inflamed and painful nodules and plaques
• The most inflammatory form of tinea capitis
• Treat with prednisone

Question 7

Deep Fungal Infections

(systemic mycoses)

Answer 7

—1° lung infection with 2° skin infection

Histoplasmosis (Ohio- bat caves, birds)

North American Blastomycosis (SW rodents)

Coccidioidomycosis (SW rodents)

Cryptococcosis (pigeon dung)

—1° skin infection

Sporotrichosis (roses)

• indurated lesions in the dermis
• More common in immunosuppresed patients
• Skin manifestations are due to a systemic infection

-Tx: PO or IV

-watch for liver toxicity

Question 8

Pityriasis rosea

Answer 8

—-Papulosquamous (eczematous) rash that is most commonly found on the trunk and proximal extremities

—-Oval scaly lesions distributed along the normal skin fold lines (Christmas tree pattern on the back).

—-“Herald” patch ->50%

-looks like ringworm, large patch followed by other oval lesions, scale in the central part of lesion, “christmas tree pattern”

-cannot be there longer than 3 months–> 2°syphilis

—-Etiology –HHV6/HHV7

—-DDX: 2°syphilis, nummular eczema, tinea corporis, guttate psoriasis

—-Clinical diagnosis

• scraping, fungal cultures
• Treatment if symptomatic, dz is self-limiting

Question 9

Necrobiosis lipoidica

Answer 9

—-Granulomatous dermatitis in plaque form- commonly found on the shins.

—-Plaques are violaceous to red with raised borders and atrophic centers with telangiectasia (start small and enlarge) and can ulcerate with trauma

—-14-65% with this finding have diabetes

—-Pathogenesis is unknown

—-Decreased sensation noted in affected skin

—DDX: sarcoidosis, 3°syphilis (gummas), fungal infections and other granulomatous conditions

-KOH Negative

Question 10

Paget’s disease of the breast

(Mammary Paget’s)

Answer 10

-—Malignant neoplasm

– contiguous spread of underlying ductal cell carcinoma of the breast

—-F>M (usually >50yrs old)

—-Unilateral – areola/nipple

—-Very recalcitrant to steroid rx

—-Red, scaling plaque with or w/o induration

—-There is “extra-mammary” Paget’s

-may or may not be associated with underlying cancer

—DDX: eczema, psoriasis, SCC in situ, impetigo

Question 11

Diagnostic Test/Treament:

Pityriasis rosea

Answer 11

Dx: RPR

Rx: Anti-itch/steroid

Referral: PCP/Infectious disease

Question 12

Diagnostic Test/Treatment:

Paget’s

Answer 12

Dx: Skin: Punch biopsy

Rx: Remove underlying carcinoma

Referral: Oncologist/surgeon

Question 13

Diagnostic Test/Treatment:

Necrobiosis lipoidica

Answer 13

Dx: Skin: Punch biopsy/ Serum: HgbA1C

Rx: IL steroid, better sugar control,

Referral: PCP/ endocrinologist

Question 14

Diagnostic Tests:

Candida/Dermatophyte

Answer 14

Dx:

KOH prep

DTM

yeast culture

Wood’s Lamp

punch biopsy