Dermatology Flashcards
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Macule (vitilgo)
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Patch (café au lat macule)
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Papule (MOLLUSCUM CONTAGIOSUM)
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Plaque (PSORIASIS)
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Nodule (BASAL CELL CARCINOMA)
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Tumour (BASAL CELL CARCINOMA)
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Vesicle (HERPES ZOSTER)
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Bulla (BULLOUS PEMPHIGOID)
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URTICARIA
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Cyst (EPIDERMOID CYST)
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Pustule (acne)
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Scale (Tinea pedis)
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Crust (IMPETIGO)
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Atrophy (STRIAE)
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Erosion (PEMPHIGUS VULGARIS: MORTEL ET URGENT)
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Ulcer (diabetic ulcer)
Redness and scaling of more than 90% of the skin, caused by dermatitis, psoriasis, drug reactions, cutaneous T cell lymphoma or idiopathic.
What’s your diagnosis?
Erythroderma, EMERGENCY –> biopsy, supportive and symptomatic treatment to relief pain and itching
- Pain out of proportion
- Skin is shiny and tense
- Does not respond to antibiotics
- Progresses at an alarming rate
- Characteristic gray–blue color within 36 hours of onset due to vessel thrombosis
- Thin, watery, malodorous fluid
- Sick and septic
What’s your diagnosis?
Necrotizing fasciitis EMERGENCY
Massive immune reaction, presents as Stevens-Johnson syndrome, SKIN DETACHMENT, high complications and mortality.
What’s your diagnosis?
Severe trug reaction –> caused by drug (allopurinol ++, antibiotics, NSAIDS, anticonvulsants) EMERGENCY –> STOP causative drug, aggressive supportive care
Reaction to a drug 2-6 weeks later?
Dress syndrome EMERGENCY –> steroids for months
Pathogenesis of atopic dermatitis?
- Lack of filaggrin protein and other proteins, oil and moisture
- Hyperreaction of TH2
- Pruritus
- Redness
- Texture
- Typical morphology and distribution: depends on the age: starts on the extensors and on the face (baby) and ends on the flexors (adults)
- Chronic or chronically-relapsing
- Personal or family history
- Increased sensitivity to irritants and environmental stimuli
- Increased rates of infections
- Associated with atopic features (allergy, asthma, allergic rhinitis)
What’s your diagnosis?
Atopic dermatitis
Investigation rules of a skin lump/bump?
ABCDE Rule
- Asymmetry (color or bordr)
- Border (irregular)
- Colour (more than 2)
- Diameter (> 6mm)
- Evolution (wks-months)
EFG Rule (nodular or amelanotic subtypes)
- Elevated
- Firm
- Growing
Most important prognosis factor of skin lump/bump?
depth/thickness
Types of Non-melanoma skin cancer (NMSC)?
- Basal cell carcinoma
- Squamous cell carcinoma
Malignant lesions of skin?
- Acquired melanocytic nevus
- Congenital melanocyte nevus
- Dysplastic nevus
- Melanomas
What is a Papulosquamous lesion?
Consists of papules = elevated primary skin lesions < 1.0 cm AND scale = surface change/laminated masses of keratin from stratum corneum
Pathogenesis of psoriasis?
DCs, T-cells, keratinocytes + endothelial cells (complicated)
- Triggers: stress, infection (strep, HIV), meds (β-blockers, TNF-α inhibitors), trauma (linear)
- Often in extensor elbows + knees, lumbo-sacral, scalp
- Psoriasis is NOT mediated by Th2 helper CD4+ T-lymphocytes
Treatment of psoriasis?
- General measures: emollients for moisturizing + avoid trauma
- Topicals: steroids, vitamin D, calcineurin inh.
- Systemics: PO meds, biologics
Pathogenesis of Lichen planus?
- T-cell mediated autoimmune damage to skin keratinocytes expressing altered self-Ags at cell surface
- Activation from self-expressed Ags attract dendritic cells = affects T-cells + get necrosis at basal layer (dermal epidermal junction of keratinocytes)
Types of Lichen planus?
- Drug-induced: onset = few mths to > 1 yr (ACE-I, diuretics, anti-malarials, NSAIDs, β-blockers)
- Classic type: multiple P’s = purple, pruritic, polygonal, planar (flat) + papules/plaques
- Oral: multiple variants; most common = white lacy reticulated (buccal mucosa, tongue)
- Genital: most common = white lacy reticulated; erosive = risk of SCC
- Nail: often isolated finding including nail thinning, longitudinal ridging + fissuring, oncholysis
- Scalp: scarring alopecia + red perifollicular papules that are scaly when active
Treatment of Lichen planus?
- General measures: emollients for moisturizing, avoid trauma, stop meds if drug induced
- Depends on: extent, location, variant, pt charact, nail disease, prior Rx + presence of Hep C
- Topics: steroids, calcineurin inhibitors, retinoids ; systemics Þ retinoids, immunosupp. meds
What is Pityriasis rosea?
Red patches common among teens + young adults
- Occurs often in spring + fall, some clustering in close contacts ; maybe linked with viral activat.
- Trauma is NOT assoc.; syphilis looks like PR + can be mistaken so WEAR GLOVES during PE!!
Pityriasis rosea treatment?
General measures = stop meds if drug-induced + emollients for moisturizing + topical steroids
What are the growth phases of the hair?
- Anagen: matrix cells grow, divide and become keratinized to form the growing hair
- Catagen: matrix proliferating cells abruptly cease proliferating so that hair bulb involutes and regresses
- Telogen: hair falls (100 days)
What is Tinea Capitis?
- Infection of the scalp by fungi
- Diagnosis: Scraping, KOH, Culture
- Treatment is oral antifungal; and topical therapy to reduce infectivity
What is Trichotillomania?
- Habitual, compulsive plucking of hair
- A well-defined area of hair loss with shortened, broken-off hairs of different lengths (frontoptemporal or parietotemporal)
- Treatment: stop + psychiatric evaluation
What is Androgenetic alopecia?
De la calvitie
What are the causes of Telogen effluvium Alopecia?
- Stress: any sever systemic disease, surgery, fever, psychological stress
- Endocrine: Hypo/hyperthyroidism…
- Nutrotional: Iron deficiency….
- Drug: Acitretin, Anticoagulant, Allopurinol…
Structures of the nail?
- Nail plate: keratinized structure which continues growing throughout life
- Lateral nail folds: cutaneous folds providing lateral borders to the nail
- Nail bed: the bed upon which the nail rests, extending from the lunula to the hyponychium
- Hyponychium: cutaneous margin underlying free nail
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What is Onychomadesis?
Complete separation of the nail plate from the bed, full but temporary arrest of growth of nail matrix, caused by trauma, dermatoligic disease (eczema), fever, viral illness, hand-foot-mouth disease
What causes Nail pitting?
holes in the plate because of matrix problem
What usually causes Acute Paronychia?
staph aureus
What usually causes Chronic paronychia?
Non purulent, glistening erythema with nail dystrophy, candida and irritation caused by saliva
What is Melanonychia?
- brown or black pigmented band along the length of nail, nail matrix nevus or lentigo, MAY BE subungual melanoma
What is Racial melanonychia?
Nail problem with darker skin phototypes, benign
What is Onychomycosis?
Fungal infection of nail unit, look at interdigital space
What are the 2 main players of urticaria?
- Mast cell: primary effector cell of urticaria
- Histamine released from the mast cells is the most probable mediator
What are the 2 Immunologic pathogenesis mechanisms of urticaria?
- IgE mediated (Type I hypersensitivity): no allergic reaction to the first exposure Þ antibody Þ reaction SECOND exposure
- Complement mediated:
- Infections: viral infection (+++), potentially in bacterial and parasitic infections
- Auto-immune/systemic disease: thyroid, collagen vascular
What are the Non-immunologic pathogenesis of urticaria?
- Chemical histamine liberators: opiates, polymyxin, thiamine in cheese, egg white, muscle relaxant, narcotics
- Physical agents: cold, heat, sunlight
What drug is important to avoid when you have an urticaria crisis?
Aspirin, NSAID
What are the possible treatment of urticaria?
- Identification and elimination or reduction of its cause
- Symptomatic relief if not able to detect or avoid cause
- Block the effect of already released histamine
- Block the release of histamine (anti-histamine type 1 and 2)
- Block mediator other than histamine (mast cell stabilizer such as Ketotifen, Leukotrine antagonists, Omalizumab)
- Modulate inflammatory, cellular and immunological component of urticaria
What is Angioedema?
- Well-demarcated non-pitting edema that occurs deeper in the dermis and subcutaneous tissue, specially in area of loose connective tissue such as the face, eyelids or mucous membrane involving the lips and tongue
- Often caused by the same pathological factors involved in urticarial
- Not itchy but painful, last 72 hours
Factors that contribute to acne?
- ↑ Sebum production
- Follicular Hyperkeratinization
- Proprionibacterium acnes
- Inflammatory response
Types of acne?
- Acne vulgaris (Adolescent acne)
- Adult acne (post- Adolescent)
- Infantile and neonatal acne
- Acne excoriée (jeunes filles, rose)
- Acne conglobate & acne fulminans (systemic manifestations)
Types of Acneiform eruptions?
- Drug-induced acne
- Occupational acne & acne cosmetica
- Acne mechanica
Treatement of acne?
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What distinguishes rosacea from acne?
comedones
Rosacea subtypes?
- Erythematotelangiectatic
- Papulopustular
- Phymatous
- Ocular
What is Hidradenitis SUPPURATIVA?
Hidradenitis Suppurativa (HS) is a chronic inflammatory skin disease characterized by persistent or recurrent flares of inflamed painful nodules, sinuses and scars in the axilla, groin, or both.