Dermatology Flashcards
Acne Rosacea
Epidemiology
Found in all skin types but with the highest prevalence in fair-skinned individuals
30-50 years old; F>M
Acne Rosacea
Etiology
Inflammatory reaction of the pilosebaceous unit of the skin on the face
Hyperplasia of the sebaceous gland
Acne Rosacea
Pathophysiology
Unknown
Acne Rosacea
Clinical Features
- Pustules and flushing with a burning sensation is common initially on the cheeks, forehead, nose and chin, causing a ruddy complexion. Worsened by alcohol, stress, eating spicy food, heat, cold, wind, sun
- Flushing, non-transient erythema, and telangiectasia
- Characterized by remissions and exacerbations
Acne Rosacea
Treatment
- Trigger avoidance is key to long tern management
- Avoid topical corticosteroids and make up
- 1st line tx: oral tetracycline ( doxy) and topical Metronidazole gel, topical azelaic acid
- oral retinoids, topical sulfur
Acne Vulgaris
Epidemiology and Etiology
- Chronic inflammation of pilosebaceous gland
- age of onset is puberty (9-11 years) that increases in severity in teenage years among men, severity decreases in adulthood
- family history of severe, cystic acne
Acne Vulgaris
Clinical Features
- Inflamed papules, pustules, nodules and cysts
Non-inflamed Comedones:
- plugging of hair follicle, nodules and cysts
- open comedone= blackhead
- closed comedone= whitehead
Inflamed type:
- increased sebum production
bacterial lipase produces irritating fatty acids causing an inflammatory reaction
Acne Vulgaris
Treatment
Systemic Antibiotics:
- mild acne: Clindamycin ( lincosamine antibiotic that inhibits protien synthesis)
- Moderate acne: doxycyclin ( tetracycline that inhibits protien synthesis)
- Severe acne: Isotretinoin ( retinoid that inhibits sebaceous gland function and regulates keratinization)
Hormonal therapy:
- oral contraceptives( reduce free testosterone levels in women)
Candidiasis
Etiology
- many species of Candidia
- opportunistic infection with predisposing factors
Candidal Paronychia
- painful red swelling of periungal skin ( toenail, fingernail)
- Management: oral antifungals if topicals are not effective
Candidal intertrigo
- erythematous rash in body folds
- predisposing factors: obesity, diabetes, systemic antibiotics, immunosuppression, malignancy
- KOH shows pseudohyphae and yeast
- management: keep area dry, topical antifungals (terbinafine) until rash clears
Carbuncles
Etiology
most commonly caused by staphylococcus aureus
Carbuncles
Clinical Features
- Abscess larger than a boil, may have multiple openings to drain pus onto the skin
- Deep- seated abscess from multiple coalescing furuncles; mass may be deep enough so it cannot drain
- red, irritatied, and may be painful when touched
Carbuncles
treatment
I&D to relieve pressure and pain
Cellulitis
Etiology
- Group A strep, Staph A (large sized wounds)
- often occurs where ther is skin damage ( blisters, burns, bites, surgical wounds, injection sites)
Cellulitis
Clinical Features
- Inflammation of the dermis and subcutaneous fat caused by bacterial infection
- Involves lower dermis/ subQ fat
- symptoms of erythema, warmth, swelling, and pain
- borders are not elevated, poorly demarcated vesicles
- the legs are the common cite of infection, regional lymphadenopathy is present
Cellulitis
Investigations
Clinical diagnosis usually
Cellulitis
Treatment
- Antibiotic: Cephalexin as 1st line treat
- If patient is diabetic: prescribe trimethoprim-Sulfamethoxazole
Felon
Definition
Subcutaneous abcess in the fingertip that commonly occurs after severe paronchyia or puncture wounds into the pad of the digit
Felon
Treatment
- elevation, warm compress
- Antibiotics, I&D
Folliculitis
Definition
Inflammation of the hair follicle due to superficial infection
Folliculitis
Etiology
- Normal non-pathogenic Bacteria
- Staph Aureus is most common
Folliculitis
Clinical Features
- lesion has a dome-shape pustule at the hair follicle where it will eventually rupture to form an small crust
Folliculitis
Treatment
Topical antibacterials ( Mupirocin); antiseptic
Furuncles
Etiology
- most commonly causes by staph aureus resulting in painful and swollen area on the skin from the accumulation of pus and dead tissue
Furuncles
Clinical features
- AKA Boil
- Deep folliculitis, infection of the hair follicle
- Common sites are hair-bearing skin areas such as highs, neck, face, axillae, groin, buttocks
- red, hot, tender and inflammatory nodules
- a yellow or white point at center of the lump that can rupture and drain pus
Furuncles
Treatment
Topical Antibiotics I&D
Herpes Simplex
Clinical Presentation
- Vesicles on an erythematous base on skin due to HSV
Transmitted through contact with erupted vesicles or through asymptomatic viral shedding
Primary Herpes Simplex
- Affects children and young adults
- Malaise, high fever, regional lymphadenopathy
- Antibody formation and latency of virus in the dorsal nerve root ganglion
Secondary herpes simplex
- recurrent form seen in adults, triggered by emotional stress, URI, fever, physical trauma
- Tingling, Pruritus, pain
HSV- 1
- seen as a cold sore that are typically seen on the face, lips but not on mucous membranes
- painful, small fluid-filled vesicles that burst leaving a yellowish crust which heals 12-21 days after outbreak
Herpes simplex
Investigation
Tzanck Smear with Giemsa stain shows multi nucleated giant epithelial cells
Herpes simplex
Treatment
Anti viral meds: Acyclovir or Valacyclovir
Impetigo
Bacterial infection of the epidermis
most common bacterial skin infection and the third most common skin disease among children
Impetigo Vulgaris
Etiology
- Group A streptococcus, Staph Aureus
- After preschool/ young adults- usu due to poor hygiene
Impetigo Vulgaris
Clinical Features
- Vesicle or pustule that ruptures and becomes yellow “honey crusted’ exudate over erosion that is surrounded by erythema.
- Common sites are face, arms, legs and buttocks
- rapid spread follows by contiguous extension or to distal areas through inoculation of other wounds from scratching
Impetigo Vulgaris
Investigations
Gram stain and culture of lesion fluid
Impetigo Vulgaris
Treatment
- Saline compress and topical antiseptic soak to remove crusts
- Topical antibacterial (e.g mupirocin)
- Systemic Antibiotics ( cephalexin)
Bullous Impetigo
Etiology
Staph Aureus
Bullous Impetigo
Epidemiology
Neonates and older children
Bullous Impetigo
Clinical Features
- small, or large, superficial fragile, thin-walled bullae
- appear quickly and spontaneously rupture and drain a clear yellow turbid fluid with no surrounding erythema
- Lesions spread usually on the face, trunk, extremities, butt and groin
Bullous Impetigo
investigation
Gram Stain and Culture lesion fluid
Bullous Impetigo
Treatment
- topical antibacterial ( mupirocin)
Oral antibiotics
Molluscum Contagiosum
Etiology
- Poxvirus (DNA Virus)- molluscum contagiosum virus
- Can be transmitted sexually, direct contact or auto- inoculation by scratching the infective viral particles out of the crater
- Common in children and sexually active young adults, common in AIDs
Molluscum Contagiosum
Clinical presentation
- Dome-shaped lesions with central crater containing white papule. Depression contains Viral Molluscum Contagiosum virus
- Common sites: eyelids, beard (likely spread by shaving), neck, axillae, trunk, perineum, buttocks
Molluscum Contagiosum
Investigation
- Non required, however can biopsy to confirm diagnosis
Molluscum Contagiosum
Treatment
- cryothperapy
- curettage
- immunocompetent, there can be spontaneous remission in 6-9 months
Necrotizing Fascitis
Definition
- rapidly progrssive inflammatory infection of the fascia, with secondary necrosis of the subcutaneous tissue
- infection spread rapidly enough that it is limb and life threatening!
Necrotizing Fascitis
Etiology
- Numerous causes ( Surgical proceedures, insect bite, intramuscular injections, local ischemia)
- Type 1 ( polymicrobial, areobes and anaerobes- e.g aures, bacteroides, Enterobacteraceae)
- Type 2: Monomicrobial, usually beta- helolytic strep
Necrotizing Fascitis
clinical features
- Pain out of propotion to clinical findings that reaches past the border of erythema
- Crepitus can be heard as anaerobes produce gas
- Edema
- Infection spread rapidly
- May appear well initially, but will become very sick later
- appearance of skin becomes black and blue( secondary to thrombosis and necrosis)
- Gangrene
Necrotizing Fascitis
Investigations
- diagnosed clinically - begin treatment right away, do not wait for investigation
- blood and tissue culture and sensitivity (C&S)
Plain film X-ray ( soft tissue gas may be visualized)
-Extreme elevation in CK which means a late sign of myonecrosis
Necrotizing Fascitis
Treatment
- IV antibiotics with penicillin clindamycin
- Emergency surgical debridement to confirm diagnosis and remove necrotic treatment
