L6 Rosacea, Acne, Insects etc Flashcards
Acne vulgaris
Common skin disorder of adolescents and young adults, disease of the pilosebaceous unit
Microcomedo
Precursor for clinical lesions of acne vulgaris due to follicular hyperkeratinization
Follicular hyperkeratinization
When follicle is producing an excess number of dead skin cells and more are sloughing off
Closed comedo/ whitehead
Accumulation of sebum due to increased sebum production and keratinous material in this step after a microcomedo
Open comedo/blackhead
Follicular orifice opened with continued distenstion, oxygen oxidized tip and makes it black
Pimple
Follicular rupture contributes to development of inflammatory lesions, bacterial byproduct causes inflammation and infection in surrounding skin
Factors contributing to acne
Androgens stimulate growth/secretory function of sebaceous glands, mechanical trauma, stress or diet
Presentation of acne vulgaris
Face/neck/chest/upper back/upper arms, sinus tracts can form
Other considerations when diagnosing acne
- Hyperandrogenism workup when female has signs of androgen excess
- Rapid appearance with virilization could be underlying adrenal or ovarian tumor
- Could be acne-inducing drugs
Tx for comedonal lesions of acne vulgaris
Topical retinoids
Tx for inflammatory lesions of acne vulgaris
Topical antimicrobial therapies
Tx for severe inflammatory acne
Oral antibiotics
Tx for abx resistant bacteria in acne vulgaris
Benzoyl peroxide
Tx for mild papulopustular and mixed acne
Benzoyl peroxide, topical abx (erythromycin, clindamycin) and topical retinoid
Tx for moderate acne
Topical retinoid + oral abx (tetracycline)+ benzoyl peroxide
Tx for severe acne
Retinoid, oral abx and benzoyl peroxide OR oral isotretinoin monotherapy
Teratogenic meds
Cause birth defects, retinoids are super contraindicated in pregnancy
Safe acne regimen for pregnancy
Oral erythromycin, topical clindamycin, topical azelaic acid
Acne rosacea
Chronic skin disorder of the central face (nose, cheeks, chin and forehead), usually emerges in 30s
Pathogenesis of acne rosacea
Abnormalities in immunity, UV damage, vacular dysfunction or inflammatory reactions to cutaneous microorganisms
4 subtypes of acne rosacea
Erythematotelangiectatic, papulopustular, phymatous, ocular
Erythematotelangiectatic rosacea
Chronic redness of central face, flushing, skin sensitivity, dry appearance, telangiectasias
Papulopustular rosacea
Papules and pustules of central face, inflammation can be confluent, no comedones
Phymatous rosacea
Tissue hypertrophy causing irregular contours, mostly nose but can be cheeks/forehead/chin, mostly men
Ocular rosacea
Often coincides with other types, can precede/coincide/follow them, dry eyes/ pain/itching/blurry vision/photosensitivity etc.
Tx for erythematotelangiectatic rosacea
First line is behavior modification, second line is laser and pulsed light therapies or topical brimonodine (vasoconstriction)
Tx for papulopustular rosacea
First line for mild/moderate: metronidazole (abx) or azelaic acid while second-line is ivermectin, severe disease is oral (tetracyclines/macrolides)
Tx for phymatous rosacea
Early is isotretinoin, advanced is surgical debulking/laser ablation
Scorpion stings
Cause major neurological toxicity by injecting venom via tail
Scorpion venom
Potent neurotoxin inactivated sodium channels causing membrane hyperexcitability (excessive neuromuscular activity and autonomic dysfunction)
Grade I scorpion stings
Produce local pain and paresthesias at sting
Grade II scorpion stings
Produce local symptoms as well as remote pain and paresthesias (often radiate proximally up affected extremity but may be in remote sites)
Grade III scorpion stings
Produce EITHER cranial nerve OR somatic skeletal neuromuscular dysfunction
Grade IV scorpion stings
Both cranial nerve dysfunction and somatic skeletal neuromuscular dysfunction
Tap sign
Sign of envenomation seen when there is local pain exacerbated by tapping near the sting site
Cranial nerve dysfunction in scorpion stings
Hypersalivation, abnormal eye movements, blurred vision, slurred speech and tongue fasiculations
Somatic skeletal neuromuscular dysfunction in scorpion stings
Fasiculations, shake and jerk extremities, opisthotonos, emprosthotonos, fever up to 104
Opisthotonos
Arching of back
Emprosthotomos
Tetanic forward flexion of body
Severe scorpion envenomations admitted to monitor
Respiratory compromise, MI, hyperthermia, rhabdo, multiple organ failure
Tx for severe scorpion envenomation
IV fentanyl for pain, IV benzos unless there is antivenom
Bee sting rxn
Most often is local with swelling, erythema and lasts for few hours to 1-2 days
Large local reaction to bee sting
Exaggerated erythema and swelling, gradually enlarges over 1-2 days, resolves in 5-10, use prednisone, antihistamines or NSAIDs
Black widows
Black with red hour-glass shaped marking on abdomen
Black widow bite
Causes small local rxn, blanched circular patcch, surround red perimeter and central punctum, venom causes catecholamine release
Presentation of black widow bite
Intermittent radiating pain, abdominal/chest/back pain and muscle spasm, diaphoresis, HA, NV
Brown recluse
Violin-shaped marking
Recluse bite
Often initially painless and progresses to severe pain, usually a red plaque or papule with central pallor, imght see 2 small puncture marks in erythema, can have vesiculation
Rare complication of recluse bite
Ulcerative necrosis where see dark, depressed center after 1-2 days, malaise symptoms and sometimes renal failure, hemolytic anemia, hypotension, DIC, rhabdo
Vitiligo
Acquired skin depigmentation due to autoimmune process directed against melanocytes
Vitiligo presentation
Milk white macules with homogenous depigmentation and well-defined borders, slowly progressive
Skin biopsy in vitiligo
Epidermis devoid of melanocytes
Hidradenitis suppurativa
“Acne inversa,” chronic inflammatory skin disorder of the hair follicle, see in axillary, inguinal and anogenital regions
Reason for hidradenitis suppurativa
Cycle of follicular occlusion, rupture and associated immune response (might be genetics, mechanical stress, obesity, smoking or diet)
Presentation of hidradenitis suppurativa
Begins with single, deep-seated inflammatory nodule that progresses, might become an abscess with purulent drainage
Skin changes in hidradenitis suppurativa
Sinus tracts, comedones, scarring, destroy pilosebaceous unit and can no longer grow hair there
Most important tx for hidradenitis suppurativa
Lifestyle modification
Tx for hidradenitis suppurativa
Local: topical clindamycin or intralesional corticosteroids, systemic abx (doxycycline or minocycline), anti-androgenic agents, surgery and then TNF inhibitors and oral retinoids in severe cases
Complications of hidradenitis suppurativa
Fistulae, stricutures/contractures, lymphatic obstruction, infectious complications, SCC, malaise, depression, suicide
