L7 Cellulitis and Other Derm Disorders Flashcards
Lymphangitis
Seen as red streak in areas of cellulitis, mark borders to notice this
Folliculitis
Inflammation of hair follicle leading to pustules and papules, itching and painful
Cause of folliculitis
S. aureus
Cause of hot tub folliculitis
Pseudomonas
Progression of folliculitis
Furuncle (well-circumscribed, painful, inflammatory nodule) and can become carbuncle/abscess
Treatment of staph. folliculitis
Usually self-limited, for moderate/ severe use topical abx (mupirocin) or oral abx (cephalexin), if MRSA then sulfa, clindamycin or doxycycline
Impetigo
Contagious superficial bacterial infection seen more in kids due to autoinoculation causing satellite lesions
3 variants of impetigo
Nonbullous, bullous or ecthyma
Nonbullous impetigo
Most common, see papules, vesicles, pustules and “honey colored crusting”- s aureus
Bullous impetigo
Vesicles enlarge and form a flaccid bulla- s aureus
Ecthyma
“Punched out” ulcers with overlying crust (like a cigarette burn)- strep bacteria
Treatment of variants of impetigo
Non-bullous and bullous is topical abx like mupirocin with oral abx for more severe, ecythma is always treated orally
Cellulitis
Inflammation of skin with a diffuse, spreading superficial infection
Pathogen of cellulitis
Beta-hemolytic strep, can be staph
2 types of cellulitis
Nonpurulent (cellulitis or erysipelas)-strep and purulent (abscess and purulent cellulitis)-staph aureus
Symptoms of cellulitis and erysipelas
Erythema, edema, warmth and can be fever
Symptoms of an abscess
Painful, fluctuant (squishy), erythematous nodule
Erysipelas
Superficial skin infection from b-hemolytic strep., seen mostly on cheeks and LE, sharply demarcated border with tender, warm and erythematous
Treatment of abscess
Most important is incision and drain, sometimes abx (because purulent)
Treatment for cellulitis
Empiric coverage for beta-hemolytic strep and staph (cephalexin or cefazolin)
Treatment of erysipelas
Empirical treatment for beta-hemolytic strep
Reasons to do I&D and abx for abscess
Abscess greater than 2 cm (or multiple), toxicity, extensive cellulitis, immunosuppression, indwelling medical device, high risk for transmission
Decolonization of MRSA
Chlorohexidine wash, mupirocin ointment intranasally
When IV abx necessary for MRSA
Extensive involvement, toxicity, rapid progression, failure PO tx, immunocompromised pt, infection near indwelling device
Cutaneous manifestations of SLE
Discoid lupus or malar/butterfly rash
Discoid lupus
Annular, erythematous, scaly plaques on sun-exposed areas (15-30% of SLE pts)
Malar/butterfly rash
Erythema on cheeks and bridge of nose, nasolabial folds spared
Tx for SLE
Topical or intralesional steroids (not face), hydroxychloroquine or other systemic med, must confirm it is not drug induced cutaenous lupus (1-5 mos after new med)
Erythema multiforme
Acute, immune mediated condition causing distinct target-like lesions
Erythema multiforma major
Will also affect the mucosa
Cause of erythema multiforme
Herpes simplex is most common, but be some drugs (NSAIDs or abx)
Tx for erythema multiforme
Usually self-limited within 2 wks, can use topical steroids or oral antihistamines, mouthwash for symptoms, no anti-virals for acute EM
Dermatitis herpetiformis
Uncommon autoimmune skin condition associated with gluten sensitivity (Celiac)
Sxs dermatitis herpetiformis
Intensely pruritic papules and vesicles seen on forearms, knees, scalp and buttocks
Tx for dermatitis herpetiformis
Dapsone and gluten elimination
Pemphigus
Group of rare, autoimmune, life-threatening, blistering disorders
Forms of pemphigus
Vulgaris, foliaceus, IgA and paraneoplastic
Acantholysis
Separation of epidermal cells from each other (caused by antibodies in pemphigus), lead to blister
Presentation of pemphigus
Mucosal involvement in oral cavity where see flaccid bullae that may spread to skin (scalp, face, axilla, groin), Nikolsky sign, S=superficial
Nikolsky sign
Gentle application of lateral pressure in an uninvolved area that causes superficial layer of skin to slough off
How to diagnosis pemphigus/pemphigoid
Lesional (routine histological exam) or perilesional (direct immunofluorescence) skin biopsies, DIF is gold standard
Tx of pemphigus
Refer to derm, main choice is systemic corticosteroids or immunosuppressive agents, can then treat oral lesions with lidocaine or acetonide or abx for secondary infection, death possible if not treated
Pemphigoid
Chronic autoimmune subepithelial blistering disorder, D=deep
Types of pemphigoid
Bullous and mucuous membrane (MMP)
Presentation of pemphigoid
Urticarial, erythematous plaques and tense bullae that do not slough off on the trunk and extremities (can see mucosal involvement)
Tx for pemphigoid
Skin care and topical or systemic corticosteroids, refer to derm, some immunosuppressive agents
Melasma/chloasma
Acquired hyperpigmentation of the skin, hormonal effect, “mask of pregnancy”
Acanthosis nigricans
Hormonal effect, common disorder associated with insulin-resistance (DM, obesity), presents with hyperpigmented velvety plaques
Hirsutism
Male pattern hair growth in women
Causes of hirsutism
Polycystic ovarian syndrome, idiopathic, cushing’s disease, insulin resistance, drugs etc
Cushing Syndrome
Excess androgens/steroid hormone, this affects pilosebeaceous unit so increased sebum/acne/ atrophy, striae
Addison’s disease
Adrenal insufficiency, hyperpigmentation of gums, buccal mucosa, elbows, knees, palms and genitalia
Pretibial myxedema
Thyroid dermopathy seen in hyperthyroidism, nonpitting, scaly thickened skin, orange peel appearance, warm, moist skin
Presentation of hypothyroidism
Dry, cool skin
Porphyrias
Metabolic disorders due to altered activity of enzymes in heme synthesis
Cause of porphyria cutanea tarda
Deficiency of uroporphyrinogen decarboxylase (UROD) in liver, leads to excess porphyrins
Sxs of porphyria cutaneous tarda
Painless sub-epidermal blistering of skin on sun exposed areas, photosensitivity, seen on dorsum of hands, forearm, face, neck and feet
Tx of porphyria cutanea tarda
Phlebotomy in order to deplete iron and prevent formation of UROB inhibitor and then low dose hydroxychloroquine
Ulcer
Pressure induced injury over bony prominences, usually related to immobility- prevention!
Stage 1 of ulcer
Intact skin with localized erythema
Stage 2 of ulcer
Partial thickness skin loss with exposed dermis, adipose not visible, no eschar (thick, dark, black scab)
Stage 3 of ulcer
Full thickness skin loss, see adipose, rolled wound edges, may see eschar
Stage 4 of ulcer
Full thickness skin and tissue loss with exposed muscle, tendon, bone or fascia, common eschar and rolled edges, fistulas
Tx of stage 1 ulcer
Transparent film for protection
Tx of stage 2 ulcer
Dressing that maintains moist wound environment (if no infection)
Tx of stage 3/4 ulcer
Debridement of necrotic tissue, appropriate dressing, maybe abx
Findings associated with tick borne illness
Erythema migrans or rocky mountain spotted fever
Why remove tick within 2-3 days
Prevent lyme disease (if so single 200mg dose of doxycycline)
Erythema migrans
Seen in early stage of lyme disease, bull’s eye appearance of rash (slightly raised, warm red with central clearing), 7-14 days after tick bite
Pathogenesis of erythema migrans
Borrelia Burgdorferi
Late stages of erythema migrans
Cardiac, arthritis and neurologic sxs, bell’s palsy
Tx of erythema migrans
Abx like doxycycline or amoxicillin
Pathogenesis of rocky mountain spotted fever
Rickettsia rickettsia
Sxs of rocky mountain spotted fever
Nonspecific sxs (fever, HA, malaise) within 2 wks, rash within 3-5 days that is macular with petechial lesions seen on ankles, wrists and trunk
Why must treat rocky mountain spotted fever early
It is lethal within 5 days!
Tx of rocky mountain spotted fever
Empiric tx based on suspicion (doxycycline)
