Dermatology Flashcards
Management of diaper rash
Frequent diaper changes Open air exposure Topical zinc oxide or petroleum jelly 1% hydrocortisone May need topical antibiotics
Perioral dermatitis is most commonly seen in:
Young women - may have history of topical corticosteroid use
Papulopustules on an erythematous base, which may become confluent into plaques with scales. May have satellite lesions. Classically spare the vermillion border
Perioral dermatitis
Management of perioral dermatitis
Topical metronidazole or erythromycin
Oral: tetracycline
Avoid topical corticosteroids!
Most common type of drug reaction/skin eruption
Exanthematous / Morbilliform Rash
Generalized distribution of “bright-red” macules and papules that coalesce to form plaques - typically begins 2-14 days after medication initiation
Drug eruption
Exanthematous/Morbilliform Rash
2nd most common type of drug eruption
Urticaria
3rd most common type of drug eruption
Erythema multiforme
Most common offending drugs with urticaria
Antibiotics and NSAIDs
Management of drug induced exanthematous/morbilliform rash
Oral antihistamines
Management of drug induced urticaria/angioedema
Systemic corticosteroids, antihistamines
Management of drug induced erythema multiforme
Topical steroids, oral antihistamines
Has an increased incidence with Hepatitis C
Lichen planus
The 5 P’s of lichen planus
Purple, polygonal, planar, pruritic papules
Lichen planus most commonly seen on:
Flexor surfaces, skin, mouth, scalp, genitals, nails and mucous membranes
Koebner’s phenomenon
New lesions at site of trauma
Seen in psoriasis and lichen planus
Fine white lines on the skin lesions or on the oral mucosa, nail dystrophy
Wickham Striae
Seen in lichen planus
Management of lichen planus
Topical corticosteroids
Antihistamines for pruritus
Rash will usually spontaneously resolve in 8-12 months
Associated with Human Herpes Virus 7
Pityriasis Rosea
This rash can mimic syphilis, so an RPR should be ordered if the pt is sexually active
Pityriasis Rosea
Solitary solman-colored macule on the trunk, followed by general exanthem 1-2 weeks later
Herald Patch
Pityriasis Rosea
Very pruritic salmon-colored papules with collarette scaling along cleavage lines in a christmas tree pattern
Pityriasis Rosea
Management of pityriasis rosea
None needed PO
Antihistamines, topical corticosteroids as needed.
Can use UVB phototherapy if severe and started early
Most common medications causes SJS and TEN
Allopurinol Sulfonamides Lamotrigine NSAIDs Anticonvulsants
SJS affects _______% of body surface area
< 10%
TEN affects ______% of body surface area
> 30%
Prodrome of fever, malaise, myalgias followed by lesions on face and trunk. Bullous and vesicle formation begins days after
SJS/TEN
Gentle pressure to the skin causes sloughing
Nikolsky Sign
Seen in SJS/TEN
Main cause of death in SJS/TEN
Sepsis and shock secondary to infection
Treatment for SJS/TEN
Admit to hospital, preferably to burn unit
Supportive care is mainstay
Most common cause of erythema multiforme
Secondary to herpes simplex infection
Multiple target-like lesions that spares the mucosa
Erythema Multiforme
Minor
Multiple target-like lesions that includes mucosal involvement
Erythema multiforme
Major
Treatment of erythema multiforme
Typically resolves after 2 weeks
Can give topical steroids and antihistamines
Intense itching, especially in the occipital area, papular urticaria may be seen
Lice
White oval-shaped egg capsules at the base of the hair
Nits Lice
Management of lice
Permethrin topical drug of choice
Safe in children > 2 y/o
If lice in hair: permethrin shampoo (leave on 10 minutes)
If pubis/body: permethrin lotion at least 8-10 hours
Second line management of lice and S/E
Lindane
Neurotoxic: headaches, seizures
Do not use after showering
Scabies cannot survive off the human body for ______ days
> 4
Intensely pruritic papules, vesicles and linear burrows
Scabies
Commonly found in the intertriginous zones including web spaces between fingers/toes and scalp
Scabies
Increased intensity of rash at night
Scabies
Diagnosis of scabies
Clinical diagnosis
Can scrape burrows with mineral oil to identify mites or eggs under microscopy
Treatment of scabies
Permethrin topical
Apply topically from neck to soles of feet for 8-14 hours before showering.
Repeat application after 1 week is recommended
Second line treatment for scabies
Lindane (cheaper)
Do not use after bath/shower
May cause seizures
Teratogenic, not used in breastfeeding women or children < 2 y/o
Key androgen leading to androgenetic alopecia
Dihydrotestosterone
Management of androgenetic alopecia
Minoxidil Oral finasteride (decreased libido, sexual or ejaculatory dysfunction)
HPV infects keratinized skin, causing excessive proliferation and retention of the stratum corneum - papule formation
Verrucae (warts)
Firm, hyperkeratotic papules between 1-10 mm with red-brown punctuations. Thrombosed capillaries are pathognomonic
Common and plantar warts (verrucae)
Numerous, small, discrete, flesh-colored papules measuring 1-5 mm in diameter.
Flat warts (verrucae)
Management of verrucae (warts)
Most resolve spontaneously within 2 years if immunocompetent
May use OTC salicylic acid and plasters
Can do cryotherapy (liquid nitrogen)
Characteristics of second degree burn - superficial partial thickness
Erythematous, pink, moist, weeping
Blistering
Most painful!
Blanches with pressure
Characteristics of second degree burn - deep partial thickness
Red, yellow, pale white, dry Blistering Not usually painful Absent capillary refill May need skin graft
Characteristics of third degree burn - full thickness
Waxy, white, leathery, dry
Painless
Absent cap refill
Characteristics of 4th degree burn
Black, charred, eschar, dry
Painless
Absent cap refill
Into underlying muscle, fat, bone
Mast cells release histamine causing vasodilation of venules and edema of dermis and SQ tissue
Urticaria
Blanchable, edematous pink papules, wheals or plaques (oval, linear or irregular)
Urticaria
Localized urticaria where the skin is rubbed (urticaria pigmentosa)
Darier’s sign
Management of urticaria
Oral antihistamines treatment of choice
Topical or oral steroids
What is included in the atopic disease triad?
- Eczema
- Allergic rhinitis
- Asthma
Usually starts in childhood
Altered immune reaction in genetically susceptible people when exposed to certain triggers - causes an increase in IgE production
Atopic dermatitis (Eczema)
Triggers for atopic dermatitis
Heat perspiration
Allergens
Contact irritants (wool, nickel, food)
Hallmark of atopic dermatitis
pruritus
Erythematous, ill-defined blisters/papules/plaques that later dries, crusts over and scales
Atopic dermatitis
Atopic dermatitis is most commonly found on:
Flexor creases
Antecubital folds and popliteal folds
Special characteristics of atopic dermatitis
Dermatographism - localized development of hives when the skin is stroked
Sharply defined discoid/coin shaped lesions found on the dorsum of the hands, feet, and extensor surfaces (knees, elbow)
Nummular eczema
Management of atopic dermatitis
- Topical corticosteroids, antihistamines for itching
2. Topical calcineurin inhibitors (Tacrolimus, Pimecrolimus) are alternatives for steroids
Annual, scaling lesions and broken hair shafts. Inflamed plaques with multiple pustules with scarring and alopecia
Tinea capitis (fungal) Ringworm
Treatment for tinea capitis
PO griseofulvin, terbinafine, itraconazole
Pruritic, scaly eruption rash between toes
Tinea pedis (athlete’s foot)
Management for tinea pedis
Topical antifungals
PO griseofulvin in uneffective
Diffusely red rash on the groin or on the scrotum
Tinea cruris (jock itch)
Management of tinea cruris
Topical antifungal
PO griseofulvin if ineffective
Erythematous plaques (circular rash with clear center and defined borders), scaling, cracking and vesicles
Tinea corporis
Management of tinea corporis
Topical antifungal
PO griseofulvin if ineffective
Diagnosis of fungal infections
KOH smear
Wood’s lamp
Overgrowth of the yeast Malassezia furfur
Tinea versicolor
Management of tinea versicolor
Topical antifungals - selenium sulfide, sodium sulfacetamide, zinc pyrithione, azoles PO (itraconazole or fluconazole if widespread)
Highly contagious superficial vesiculopustular skin infection that typically occurs at site of superficial skin trauma
Impetigo
Impetigo occurs primarily on exposed surfaces of the
Face and extremities
Risk factors for impetigo
Warm, humid conditions
Poor personal hygiene
Vesicles, pustules that have a characteristic honey colored crust
Nonbullous impetigo
Most common causes of impetigo
Staph aureus
Vesicles form large bullae (rapidly), which rupture and leave thin “varnish-like crusts,” fever and diarrhea also
Bullous impetigo
Management of impetigo
- Mupirocin (Bactroban) topical drug of choice TID x 10 days.
- Wash area gently with soap and water
Management of impetigo if extensive disease or systemic symptoms (fever)
Systemic abx - cephalexin, dicloxacillin, clindamycin, erythromycin, azithromycin