Dermatology Flashcards
Atopic Dermatitis aka Eczema
Chronic relapsing skin disorder
Type I IgE hypersensitivity reaction
a/w Allergic triad
- Asthma
- Allergic Rhinitis
- Atopic dermatitis
Sxs:
- Pruritic rash
- Dry, scaly skin - lichenification, fissures, worsening rash
- usu flexor surfaces for adults (neck, eyelids, forehead, face, wrists)
- facial & extensor surfaces for children (elbows, behind knees)
Tx:
- Moisturizers, and emollients - Cetaphil or Eucerin
- Topical CS for flare ups
- Topical Calcineurin inhibitors - mod to sev dz
- Tacrolimus and Pimecrolimus
- UV photo therapy for refractory
Bullous Pemphigold
Rare, acq’d autoimmune subepidermal blistering skin disorder = autoantibodies (IgG) against hemidesmosomes
Sxs:
- Large bullae and crust on axillae, thighs and abd
- more tense, less fragile, deeper than pemphigus vulgaris
- Negative Nikolsky skin (bleeding when scratched)
Dx:
- skin bx - direct immunofluorescence exam
- deposits of IgG and C3 basement membrane
Tx:
- Systemic CS - high doses until remission
- Azathioprine?
Burns - Degrees and Rule of 9s
Rule of 9s (pic)
1st degree - sunburn
- erythema involved tissue
- skin blanches w/ pressure
- skin may be tender
2nd degree - partial thickness
- skin is red and blistered
- skin very tender
3rd degree - full thickness
- burned skin is tough and leathery
- skin non-tender
4th degree - Into bones and muscles
Burns - minor/major, tx
Minor
- < 10TBSA adults
- < 5 TBSA young/old
- <2% full thickness
- not involve face, hands, perineum, feet, cross major joints or be circumferential
Major
- > 25% TBSA adults
- >20% TBSA young/old
- >10% full thickness burn
- Burns w/ face, hands, perineum, feet, cross major joints/circumferential
Tx:
- monitor ABCs, fluid repletion, topic abx
- cleans w/ mild soap and water, no direct ice
- Irrigate chemical burns w/ running water x 20 ms
- topic abx for superficial burns
- fingers and toes wrapped individually to prevent maceration and gauze placed btwn them
Cellulitis
Acute bacterial skin infection from portal entry
MCC - GA Strep or S. aureus; animal bites via P. multicida or human bites E. corrodens
Sxs:
- Pain, warmth, swelling
- Spreading erythema (mark w/ pen) - non blanching
- flat margins and not well demarcated
Dx:
- would culture f/u in 48 hrs
Tx:
- Mild cellulitis - MSSA
- Cephalexin or Dicloxacillin
- Cat bite - Augmentin or doxy if PCN allergic
- Puncture wound - Cipro
- MRSA
- Bactrim 1 DS tab PO BID
- Clindamycin 300-450 mg PO
- Doxycyclin 100 mg PO BID
Contact Dermatitis: Allergic vs Irritant
Allergic Contact Dermatitis - MCC poison ivy (Rhus dermatitis)
- delayed Type IV hypersensitivity reaction
- 10-14 days
- re-exposure appears w.in 12-48 hrs
Irritant Contact Dermatitis - MCC chemical Irritants or diaper rash
- Cleaners, solvents, detergents, urine, feces
Sxs:
- Acute - well demarcated erythema and exudative lesions
- Burning, itching, erythema
- Eczematous eruptions
- Chronic - plaque and scaling - lichenification
Dx - patch gesting
Tx:
- Localized - mid or high potency CS
- Triamcinolone 0.1% or Clobetazol 0.05%
- >20% BSA - systemic CS
- Prednisolone 0.5-1mg/kg/d
- should resolve w/in 12–24 hrs
Drug Eruptions
adversed cutaneous reaction to admin of a drug; usu w/in past 6 wks
Sxs:
- skin reactions are MC
- can be mild to severe (multiorgan damage)
- Pruritus, mild fever => systemic sxs fever, malaise, HA
Dx
- clinical - bacterial, viral or underlying skin dz (cutaneous lymphoma)
Tx
- withdraw offending agents
- monitor for sxs of CV collapse - anaphylaxis, DRESS, SJS/TEN, extensive bullous rx, generalized erythroderma
- Don’t rechallenge w/ drugs causing urticaria, bullae, angioedema, DRESS, anaphylaxis
- anaphylaxis or widespread uritcaria => epinephrine 0.2-0.5mg & prednisone to prevent recurrence
- Antihistamines
Erysipelas
Form of Cellulitis = MC d/t Group A Strep (pyogenes)
Sxs:
- Usu face or LE
- Pain, warmth
- Superficial, well demarcated erythema
- fever, chills
- +/- bullae
Dx - culture
Tx:
- mild - Pencillin G (or erythromycin/clinda if PCN allergic)
- Mod - bactrim or PCN/Cephalexin
- Severe - IV Vanco
Hand Foot Mouth Disease
Viral Exanthems
Coxsackie type A virus
Children < 10 yo; very contagious in 1st week - spread via direct contact w/ saliva and mucus
Herpangina Is blister located to just the mouth
Sxs:
- Small, tender, erythematous papules or vesicles on pharynx, mouth, hands, feet
- Punched out, cratered
- Irritability
- Loss of appetite
- General irritability
- Feeling unwell
Dx - clinical
Tx
- clears up in 10 days
- pain meds for sxs relieve
- Good hand hygiene
Herpes Zoster
Varicella (chickenpox) - reactivation causing maculopapular rash along one dermatome
Dx - Tzanck Smear - multinucleated giant cells
Zoster Opthalmicus
- shingles w/ CN V - dendritic lesions on slit lamp
Zoster Oticus (Ramsay-Hunt Syndrome)
- facial n CN 7, otalgia
- lesion on ears, auditory canal and TM
- facial palsy auditory symptoms
- ddx Bell’s palsy
Tx:
- Acyclovir, valacyclovir, famciclovir - given w/in 72 hrs to prevent post-herpetic neuralgia
- Post herpetic Neuralgia pain > 3 mos- parethesias or decreased sensation
Impetigo
Highly contagious bacterial skin infx - MCC S aureus, S pyogenes or both
Children or adults
Begins as papules -> vesicles -> ruptured to form thick, adherent, golden crust
Sxs:
- Red sores form around nose and mouth
- Yellow-brown/golden crust
- Non-painful and pruritic = honey colored and weeping
Dx - Gram stain and culture
Tx:
- Topical Mupirocin, dicloxacillin or cephalexin for more severe illness
- MRSA - Doxy, Clinda or Bactrim
- Abx x 7 d
Lice
Sxs:
- pruritic scalp, body (corporis), or groin (pubis)
- Small white specs on hair shafts
Dx:
- observation of nits and lice - nits are ovoid, grayish white eggs
Tx:
- Permetherin topical 1% - shampoo and cream
- Launder fomites aka sheets in > 131 F or 55C
- Seal toys in bag for 72 hrs
- PO Ivermectin for resistant cases
Pilonidal Disease
abn skin growth at tailbone/natal cleft that contain hair and skin
MC teens/20s, Males, Obese, sedentary, local trauma
eti - sinus tract, abscess
Sxs:
- pain, discomfort
- swelling above anus or near tailbone
- drainage of pus and blood
Dx - clinical
Tx:
- I&D with wound debridement - look for sinus tract
- Abx to prevent cellulitis
- Cefazolin + metronidazole
- Augmentin
Pressure Sores
Sacrum and hip most often affected; resposition every 2 hrs
Stage 1 - erythema of localized area, usu non-blanching over bony surfaces
- Aggressive preventative measures, thin-film dressings for protection
Stage 2 - partial loss of dermal layer, resulting in pink ulceration
- Occlusive dressing to maintain healing
- transparent films, hydrocolloids
Stage 3 - full dermal loss often exposing subcutaneous tissues and fat
Stage 4 - full thickness ulceration exposing bone, tendon, or muscle. Osteomyelitis might be present
- debridement of necrotic tissue
- Exudative ulcers - will benefit from absorptive dressings - calcium alginates, foams, hydrofibers
- Dry Ulcers - occlusive dressing to maintain moisture, hydrocolloids, hydrogels
Pressure Sores
