Derm part 1 Flashcards
PE of diaper dermatitis
An erythematous scaly diaper area often with papulovesicular or bullous lesions, fissures, and erosions
Causes of diaper dermatitis
Overhydration of the skin Maceration Prolonged contact with urine and feces Retained diaper soaps Topical preparations More than 3 diarrheal stools/day Adverse effects of oral abx Early sign of biotin deficiency
Tx of diaper dermatitis
Zinc oxide ointment Acetyl tocopherol Pure white petrolatum ointment Aquaphor 1-2-3 paste
Sx of perioral dermatitis
Sensation of stinging and burning
H/o long-term use of topical steroids
PE of perioral dermatitis
Skin lesions occur as grouped reddish papules, papulovesicles, and papulopustules on an erythematous base with a possible confluent aspect
Primarily a perioral distribution
Causes of perioral dermatitis
Topical steroid preparations Cosmetics UV light, heat and wind Microbiologic factors Hormonal factors
Tx of perioral dermatitis
Therapy similar to that for rosacea
Topical praziquantel
S/sx of lichen planus
Insidious lesions that usually develop on flexural surfaces of the limbs
After a week later, generalized eruption.
Pruritis
Papules are violaceous, shiny, and polygonal
Wickham striae
Labs for lichen planus
Direct immunofluorescence study in lichen planus
Tx for lichen planus
Mild cases: fluorinated topical steroids
Light therapy
Retinoid-like agents
S/sx of pityriasis rosea
Herald patch of 2-5 cm that is pink and oval with a central clearing
1-2 wks later, 0.5-2 cm macules with fine, branlike scale arranged parallel to skin tension lines
Where is the herald patch found in pityriasis rosea?
Breast
Lower torso
Proximal thigh
Tx of pityriasis rosea
Manage any pruritis with oral antihistamines, phototherapy and low-potency topical corticosteroids
PE of erythema multiforme
Abrupt onset of round, deep red, well-demarcated macules and papules with a dusky gray or bullous center
Involves <10% of the body
Target lesion of erythema multiforme
Three concentric rings:
- Outermost is red
- Intermediate is white
- Center is dusky red or purple
Most common cause of erythema multiforme in children
Herpes simplex virus
Tx of erythema multiforme
Symptomatic
Oral antihistamines to suppress pruritus, stinging, and burning
What usually precedes SJS or TEN?
Prodrome of fever, malaise, and upper respiratory sx 1-14 days before the onset of cutaneous lesions
Presentation of SJS/TEN
Red macules that appear suddenly and tend to coalesce into large patches with a predominant distribution over the face and trunk
Lesions evolve rapidly into bullae and areas of necrosis
Difference between SJS, SJS/TEN, and TEN
SJS is <10% of body surface area
SJS/TEN is 10-30% of body surface area
TEN is >30% of body surface area
What areas are involved in SJS/TEN?
Any mucosal surface may be involved
What are the most common causes of SJS/TEN in children?
Drugs -NSAIDs -Sulfonamides -Anticonvulsants -Antibiotics Mycoplasma pneumoniae infections
Tx of SJS/TEN
Discontinuation of offending agent Supportive care Meticulous wound care Parenteral or nasogastric feeding Careful fluid management and monitoring of electrolytes
Contributing factors of acne
Gender Age Genetic factors Environment Stress
Pathogenesis components of acne
Increased sebum production
Hyperkeratosis
Bacterial proliferation
Location of acne
Face
Upper chest
Back
What does superficial plugging of the pilosebaceous unit result in?
Open (blackhead) comedones
Closed (whitehead) comedones
What is the third stage of acne?
Inflammatory papules and pustules
What is the fourth stage of acne?
Cystic acne
Diagnostic tests for acne
Screening tests if there are signs of PCOS or an underlying androgen-secreting tumor
Tx of acne
Topical keratolytic agents Topical retinoids Topical antimicrobials/antibiotics Combination of topical keratolytic agent and topical antimicrobial Oral antibiotics Oral isotretinoin
RFs of atopic dermatitis
Occurs more frequently in urban areas and in higher socioeconomic classes
FHx of atopy
S/sx of atopic dermatitis
Xerosis
Pruritis
Erythematous papules or plaques with ill-defined borders and overlying scale or hyperkeratosis
Excoriation and lichenification
Locations of atopic dermatitis in infants
Face and extensor surfaces of the extremities
Locations of atopic dermatitis in children
Flexural surfaces
- Antecubital and popliteal fossae
- Wrists
- Ankles
- Hands
- Feet
What secondary infections are present with atopic dermatitis?
S. aureus
Less commonly S. pyogenes
Signs of concomitant infection in atopic dermatitis
Acute worsening of disease in an otherwise well-controlled patient
Resistance to standard therapy
Fever
Presence of pustules, fissures, or exudative or crusted lesions
What are the three components of atopic dermatitis tx?
Frequent liberal use of bland emollients to restore the skin barrier
Avoidance of triggers of inflammation
Use of topical anti-inflammatory medication
Tx of atopic dermatitis
Avoid trigger exposure
Topical corticosteroids- ointments are preferred
Immune modulators
Sedating antihistamines during flares
Short-term administration of systemic corticosteroids
Ultraviolet light therapy
Complications of atopic dermatitis
Secondary bacterial infections- most common is secondary impetigo
Eczema herpeticum
What are the two subtypes of contact dermatitis
Irritant
Allergic
Irritant contact dermatitis
Observed after the skin surface is exposed to an irritating chemical or substance
Allergic contact dermatitis
A cell-mediated immune reaction (type IV)
Characteristics of irritant contact dermatitis
Ill-defined, scaly, pink or red patches and plaques
On dorsal surfaces of the hands
Characteristics of allergic contact dermatitis
Acute lesions are bright pink, pruritic patches, often in linear or sharply marginated bizarre configurations
Within the patches are clear vesicles and bullae
Timeline for acute allergic contact dermatitis
Could be delayed for 7-14 days after the exposure if the pt has not been sensitized previously
Characteristics of chronic allergic contact dermatitis
Often mimics atopic dermatitis
Labs for contact dermatitis
Often clinical dx
Patch testing for difficult cases
Tx of contact dermatitis
Topical corticosteroids
Oral antihistamines
How does seborrheic dermatitis classically present in infants?
Cradle cap or dermatitis in the:intertriginous areas of the: -Axillae
- Groin
- Antecubital and popliteal fossae
- Umbilicus
How does seborrheic dermatitis present in adolescents?
Dandruff
Areas prone to seborrheic dermatitis
Scalp Eyebrows Eyelids Nasolabial folds External auditory canals Posterior auricular folds
Characteristics of cradle cap
Thick Greasy and waxy Yellow-white scaling Crusting of the scalp May extend to the face and posterior folds
Characteristics of dandruff
Fine
White
Dry scaling of the scalp with minor itching
Dx of seborrheic dermatitis
Fungal cultures and KOH to help differentiate from tinea capitis
Tx of seborrheic dermatitis
Frequent shampooing
Infants- oil may be gently massaged into the scalp and left on for a few minutes before gently brushing out the scale and shampooing.
