Dermatology - Over Simplified Flashcards
Herpes simplex
cause: Herpes simplex virus 1/2 Presentation: Vesicles -> weeping -> yellow crusting Treatment: Acyclovir Complications: Superinfection with staph, dissemination in primary infection
Varicella zoster
cause:
Herpes simple virus 2/chickenpox in children
Presentation;
Unilateral vesicles along dermatomes, dissemination in immune compromised
Treatment: Acyclovir
Complications: Neuralgia, superinfection
Viral warts
Cause: Human papilloma virus Presentation: Papilomous cauliflower like lesions with moist macerated vascular surface Coalesce to form huge fungatating plaques Treatment: Preventative with HPV vaccine Imiquimod - immune modulator that causes wart regression Complications: Cervical, facial, vaginal, anal cancers
Molluscum contagiosum
Cause: Pox virus Presentation: Umbilicated pappules with dimpled center Treatment: Destructive methods, iodine Complications: Superinfection
Lichen planus
Cause:
T lymphocytes produce cytokines (ICAM-1) in the dermo-epidermal junction causing keratinocytes apoptosis
Drugs (beta blockers, quinine, captopril), hepatitis
Presentation:
Planar (flat-topped), purple, polygonal, pruritic papules and plaques on extremities
Treatment:
Stop drugs or any cause
Topical steroids (clobetasol), retinoids
Antihistamines → for itch
Systemic prednison + UVA/B → 1-3 months
Dermatopyte infection
Cause:
Trichophyton, microsporum, epidermophyton
Presentation:
Foot- soggy interdigital plaques, diffuse dry scaling on soles, reoccurring vessication Nails- yellow, crumbly nails, spereation of nail from bed, thickening of nail,
Groin- sharp, well demarcated plaques with peripheral scaling
Trunk/limbs- plaques with scaling and erythema
Scalp inflammation, bald spots with scaling
Treatment:
Clotrimazole, fluconazole, intraconazole, griseofusin
Complications:
Permanent scaring alopecia
Onychomycosis
Thickening of nail that leads to nail bed separation seen in fungal nail infections such as tineapedis
Candida
Cause:
Candida albicans
Presentation:
Oral thrush usually in immune compromised, nail bed infection
Treatment:
Topical or systemic imidazoles, fluconazole, amphotericin
Pityriasis versicolor
Cause:
Commensal yeast (pityrosporium orbiculare)
Presentation:
Flaky discoloured patches on chest and back
Treatment:
Imidazoles, fluconazole
Erysipelas
Cause:
Streptococcus pyogenous infection of dermis/hypodermis
Presentation:
Flu like symptoms, well defined advancing edges of redness, blistering of skin
Treatment:
Penicillins, anti staph penicillins
Complications: Sepsis
Staph skin infection
Cause: Staphylococcus aureus
Impetigo- bulbous with well demarcated borders
Furcolosis- infection of hair follicles, red tender nodules with puss Carbuncle- swollen, painful, pussing hair follicles
Scaled skin syndrome/toxic shock syndrome
Treatment:
Penicillin to vancomycin to 4th gen cefalosporins
Scabies
Cause: Mites
Presentation:
Itch, fissure on skin with eggs
Treatment: Permethrin
Atopic dermatitis
Cause: IgE response to certain stimuli Presentation: Itch, leathery dry skin that started with vesicles and weeping, on flexor surfaces Treatment: Emollients, topical steroids
Contact eczema
Cause:
Delayed type 4 hypersensitivity due to contact with known stimulus, ie. Poison ivy
Presentation:
Erythema, vesicles, weeping at the sight of contact with allergen
Treatment:
Stay away from allergen
Topical corticosteroids fo temporary relief
Seborrhoeic eczema
Cause:
Body overreaction to yeast that lives on skin, stress, cold dry weather, immune system response
Presentation:
Dry scales around nose, scalp, or trunk. Dandruff
Treatment:
Shampoo with ketoconazole, hydrocortisone, topical corticosteroids/calcineurin inhibitors tacrolimus
Angioedema
Cause:
Diffuse swelling due to edema in subcutaneous tissue
Presentation:
Abrupt and short-lived swelling of the skin and mucous membranes. All parts of the body may be affected but swelling most often occurs around the eyes and lips
Treatment:
antihistamines, oral corticosteroids (prednisone), immunosuppressants (ciclosporin)
Types of urticaria
Cause: Mast cell degranulation due to interaction with potential stimuli Presentation: red itchy Wheel lasting less than 24h Types: Physical (cold, solar, heat, cholinergic, dermatographism, delayed pressure) Hypersensitivity Autoimmune Parmalogical Contact Treatment: Antihistamines,
Stevens Johnson syndrome and Toxic epidermal necrolysis
Difference:
1-10% of body covered is SJS, >30% is TEN
Cause:
Drugs (sulfonemides, antiepileptics, allopurinol)
Presentation:
Prodromal period with fever/ malaise
Painful macular exanthem (skin is red, painful, detaches in sheets) Nikolski sign positive
Treatment:
Identify and stop cause
Symptomatic management (topical steroids, emollients)
Erythema Nodosum
Cause:
Inflammation of subcutaneous fat due to a type 4 hypersensitivity in response to an infection
Presentation::
Tender red nodules on the legs and forearms
Treatment:
Identify and eliminate cause Symptomatic treatment, NSAIDs, potassium iodide