Common Skin Disorders Flashcards
Hereditary: either a family or a personal history of asthma, allergic rhinitis, or AD
Infants: cheeks, extensors, trunk
Child: flexors, neck
Adolescent: hands
Dry skin and horny follicular papules
Exacerbated by dry skin, contact sensitivity, stress and anxiety
Topical hydrocortisone or fluocinolone
Moisturizers after the topical steroids
Cloxacillin or Cefalexin for infected lesions
ATOPIC DERMATITIS
Lesions are limited to the area of contact the external substance
Poison ivy, nickel, cosmetics, perfume, soap
Form of cell-mediated injury
Management:
- Keep the area dry
- Use of mild to moderate topical steroids (HYDROCORTISONE or FLUOCINOLONE)
- treat superimposed bacterial infection first with either CEFALEXIN or CLOXACILLIN
ALLERGIC CONTACT DERMATITIS
Due to strong chemicals that penetrate the epidermal barrier readily, or weaker chemicals that penetrate a faulty epidermal barrier, or substances that remove intracellular lipid
Management:
- Keep the area dry
- Use of mild to moderate topical steroids (HYDROCORTISONE or FLUOCINOLONE)
- treat superimposed bacterial infection first with either CEFALEXIN or CLOXACILLIN
IRRITANT CONTACT DERMATITIS
Unknown mechanism: excessive sebum accumulation on scalp, face, midchest, perineum
Greasy scalp (cradle cap), greasy scales in nasolabial folds or eyebrows
Physiologic overproduction of sebum in the 1st 6 months of life
Topical low potency steroids; keratolytic shampoo
SEBORRHEIC DERMATITIS
Erosions covered by moist, honey-colored crusts in face, nares, extremities
Bullous- lesion with central moist crust and an outer zone of translucent blister
Staph aureus, group A streptococcus
Depth of invasion is until the upper epidermis
Microscopic breaks in the epidermis like trauma of scratching the skin
CLOXACILLIN or CEFALEXIN with or without MUPIROCIN
IMPETIGO
Entire epidermis is involved
Firm, dry, dark crust with surrounding redness and induration
Both impetigo and ecthyma: CLOXACILLIN 50-100mg/kg/day every 6 hours
Good personal hygiene
ECTHYMA
Tender, warm, erythematous plaques with ill- defined borders
Regional lymphadenopathy and fever
Preceding puncture wound or other penetrating trauma to the skin is noted
STREP, STAPH, H. INFLUENZAE
- invasion of bacteria into the deep dermis and subcutaneous fat
Management:
- PENICILLIN 600,000- 1.2 M units/kg/day q 6 hours for streptococci
- OXACILLIN 100-200 mg/kg/day q 6 hours for staphylococci
- AMPICILLIN (100-200 mg/kg/day) + Chloramphenicol (50-100 mg/kg/day) for H. Influenzae
- CEFUROXIME, CEFTRIAXONE, or CEFOTAXIME
CELLULITIS
Tender erythematous nodule
Management:
- CLOXACILLIN or CEFALEXIN
- I & D
Furunculosis
Confluence of several adjacent areas of furuncles producing a tender red tumor
Management:
- CLOXACILLIN or CEFALEXIN
- I & D
Carbuncle
Long-standing carbuncle that becomes soft and fluctuant
Management:
- CLOXACILLIN or CEFALEXIN
- I & D
Abscess
S. aureus of phage group II elaborates a staph. exfoliatin A carried via the circulation to the skin —> acts on the cells surface of the epidermal granular cells —> injury results in intraepidermal separation of the cells within the granular layer —> shedding of the entire granular layer and stratum corneum when a minor trauma occurs
Spectrum: from bullous impetigo to generalized involvement
Faint red eruption in face, neck, axilla and groin
Skin rapidly becomes tender with crusting around the mouth, eyes and neck
Mild rubbing of the skin results in epidermal separation leaving a shiny, moist, red surface – (+)Nikolsky sign
OXACILLIN; fluid and electrolyte correction; bland ointments during the desquamation phase
STAPHYLOCOCCAL SCALDED SKIN SYNDROME
MALASSEZIA FURFUR invades the stratum corneum which thrives hot, humid climate and colonizes the skin by adolescence
KOH scraping: short curved hyphae and circular spores (“spaghetti and meatballs”)
MICONAZOLE, CLOTRIMAZOLE, or FLUCONAZOLE
SELENIUM SULFIDE 2.5% overnight application once weekly for 4 weeks
TINEA VERSICOLOR
Colonization of the oral cavity, GIT, and vagina AOG healthy individuals by Candida albicans is normal
Moisture, warmth, and breaks in the epidermal barrier permit overgrowth and invasion of the epidermis
C. Albicans generates inflammation by activation of the complement system within the skin and attraction of neutrophils to skin sites –> keratolytic proteases allow them to penetrate the epidermal barrier
Neonates & infants: white plaques on a red base (thrush) in the buccal mucosa; intertrigenous areas (beefy erythema with elevated margins and satellite red plaques) like inframammary, Axillary, neck & inguinal body folds
Adolescent females: whitish plaques on red mucous membrane of vulvovaginal areas with cheesy vaginal discharge
Oral thrush: oral NYSTATIN 4x/day for 5 days
Skin: KETOCONAZOLE, MICONAZOLE, CLOTRIMAZOLE
CANDIDIASIS
Due to Sarcoptes scabiei where the female mite remains in the stratum corneum — deposits eggs and dies after 30-40 days
Transmission of scabies requires human contact and itching - occurs 3 weeks after infestation
Pruritic papules on the abdomen, dorsa of he hands, flexors, periaxilla, genitalia, interdigits
Secondary impetigo is common
Brown crusted nodules on the trunk: S-shaped burrows are diagnostics
Permethrin 5% for 8-14 hours has a 98% cure rate
Lindane lotion one 6-hour application
Itching may persist for 7-10 days after successful therapy
SCABIES
Benign tumors of capillary endothelium
Pale white to gray-blue macule; telangiectatic; papule form
Growth phase followed by regression in the 2nd year of life
By 9 years old, 90% have reached maximal progression
Oral steroids at 2mg/kg
Platelet trapping with consumptive coagulopathy (KASABACH-MERRITT SYNDROME); systemic steroids and fresh frozen plasma; interferon; pulsed dye laser if ulcerated
HEMANGIOMA
Due to poxvirus that induces epidermal cell proliferation
Type 1 - extremities, head & neck
Types 2 & 3 - genital lesions
Incubation period of 2-7 weeks and thchild is contagious as long as activ lesions are present
White or yellow 1-6mm discrete papules with a central umbilication
Some may extrude keratinous contents from the center
Around the eyes, axilla, proximal extremities
Removal with a sharp curette
Recurrence are common
MOLLUSCUM CONTAGIOSUM
Type 1 or juvenile onset - AD
HLA-Cw6 & HLA-DR7 are increased
Inflammation with epidermal proliferation
Clinical dx: thick silvery scales, nail involvement and isomorphic phenomenon (lesions develop in sites of skin trauma several days after the event)
Scalp, ears, eyebrows, elbows, knees, gluteal crease, genitalia & nails
Itching is a variable feature
Management:
- Therapy aims to retard epidermal proliferation
- Topical steroids - 2-3 weeks temporary improvement followed by phototherapy (UVL)
- salicylic acid 3% for the scalp
PSORIASIS
Due to allergic reactions to drugs, climate, food, insect bites, etc
Histamine directly released from cutaneous mast cells
Red, raised, irregular border, pruritic wheals scattered over the body which are evanescent - URTICARIA
subcutaneous lesions are called ANGIOEDEMA
Hypersensitivity Reaction
Oral antihistamines
Avoid the offending substance
Diphenhydramine 1mg/kg (max 50mg) IM
Urticaria
Due to a HSV specific host respond to HSV antigens expressed in keratinocytes within the target lesion
Oval or round, fixed, red skin lesions with dusky central zone - target or iris lesion
Recurrent; dorsal surface of hands and extensors, palms & soles
Absent systemic symptoms and signs
Wet compress and oral antihistamines
ERYTHEMA MULTIFORME
Due to genetic susceptibility to injury – toxic effect on keratinocytes and mucosal epithelial cells
Related to drug infections with NSAIDs, sulfonamide and anticonvulsants
Serious and life-threatening
Large areas of epithelial necrosis
Prodrome of fever, headache, sore throat, malaise
Severe mucosal involvement with extensive mucosal necrosis and always involves at least 2 mucosal surfaces (oral, genital, urethral, GIT, lower respiratory tract)
Rapid progression from central blisters to severe epidermal necrosis with loss of epidermis leaving a denuded skin — hemorrhagic crusts on the lips
Management:
- Discontinue the offending drug
- fluid and electrolyte replacement; prevention of secondary bacterial infection; ophthalmologic consultation
- no evidence of effect of systemic steroids
STEVEN JOHNSON SYNDROME
