Musculoskeletal, Skin, and Connective Tissue- Dermatology and pharmacology Flashcards
Skin layers
epidermis, dermis, subcutaneous fat
Epidermis layers: Basale, Spinosum, Granulosum, Lucidum, Corneum
Epithelial cell junctions
- Tight junction
- Adherens junction
(zonula occludens)- composed of claudins and occludins.
(belt desmosome, zonula adherens)— forms “belt” connecting actin cytoskeletons of adjacent cells with CADherins. Loss of E-cadherin promotes metastasis
Epithelial cell junctions
- Desmosome
- Gap junction
- Hemidesmosome
(macula adherens)—structural support via intermediate filament interactions. Autoantibodies to desmoglein pemphigus vulgaris.
channel proteins called connexons permit electrical and chemical communication between cells.
Connects keratin in basal cells to underlying basement membrane. Autoantibodies bullous pemphigoid.
Dermatologic macroscopic terms
Pag. 462
Dermatologic microscopic terms
- Hyperkeratosis
- Parakeratosis
- Hypergranulosis
- Spongiosis
- Acantholysis
- Acanthosis
thickness of stratum corneum (psoriasis)
Retention of nuclei in stratum corneum (psoriasis)
thickness of stratum granulosum (liquen planus)
Epidermal accumulation of edematous fluid in intercellular spaces (Eczematous dermatitis)
Separation of epidermal cells (Pemphigus vulgaris)
Epidermal hyperplasia (Increase spinosum) (Acanthosis nigricans)
Pigmented skin disorders
- Albinism
Normal melanocyte number with decrease melanin production due to low tyrosinase activity or defective
tyrosine transport. risk of skin cancer.
Pigmented skin disorders
- Melasma (chloasma)
Hyperpigmentation associated with pregnancy (“mask of pregnancy”) or OCP use.
Pigmented skin disorders
- Vitiligo
Irregular patches of complete depigmentation. Caused by autoimmune destruction of melanocytes.
Seborrheic dermatitis
Erythematous, well-demarcated plaques with greasy yellow scales in areas rich in sebaceous glands, such as scalp, face, and periocular region.
Common in both infants and adults, associated with Parkinson disease.
Possibly associated with Malassezia spp. Treat with topical antifungals and corticosteroids.
Acne
- Etiology
- Treatment
Multifactorial etiology— sebum/androgen production, abnormal keratinocyte desquamation, Cutibacterium acnes colonization, and inflammation.
Treatment includes retinoids, benzoyl peroxide, and antibiotics
Atopic dermatitis (eczema)
Pruritic eruption, commonly on skin flexures. Often appears on face in infancy and then in antecubital fossa in children and adults.
Associated with other atopic diseases.
Mutations in filaggrin gene predispose.
Allergic contact dermatitis
Type IV hypersensitivity reaction that follows exposure to allergen. Lesions occur at site of contact (eg, nickel, poison ivy, neomycin).
Melanocytic nevus
Common mole. Benign, but melanoma can arise in congenital or atypical moles. Intradermal nevi are papular. Junctional nevi are flat macules.
Pseudofolliculitis barbae
firm, hyperpigmented papules and pustules that are painful and pruritic. Located on cheeks, jawline, and neck.
Commonly occurs as a result of shavin
Psoriasis
Papules and plaques with silvery scaling, especially on knees and elbows. Acanthosis with parakeratotic scalin. Munro microabscesses. Auspitz sign
Associated with nail pitting and psoriatic arthritis.
Rosacea
Inflammatory facial skin disorder characterized by erythematous papules and pustules.
May be associated with facial flushing in response to external stimuli (eg, alcohol, heat).
Phymatous rosacea can cause rhinophyma (bulbous deformation of nose).
Seborrheic keratosis
Flat, greasy, pigmented squamous epithelial proliferation with keratin-filled cysts (horn cysts). Looks “stuck on.”
Leser-Trélat sign
Sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (eg, GI, lymphoid).
Verrucae
Warts; caused by low-risk HPV strains. Soft, tan-colored, cauliflower-like papules. Condyloma acuminatum on anus or genitals