Dermatology Flashcards
45 y-o patient thin blisters, (+) Nikolsky sign: skin detachment with gentle traction, and involvement of oral mucosa.
Dx, next step, tx?
Pemphigus vulgaris (antibodies against desmosomes)
Next step:
Biopsy with tombstone effect and immunofluorescence throughout the epidermis.
Tx:
- 1st: high-dose steroids
- When controlled: mycophenolate mofetil, rituximab
75 y-o patient with thick blisters, (-) Nikolsky sign and not involvement of oral mucosa.
Dx, next step, tx?
Bullous Pemphigoid (antibodies against hemidesmosomes)
Next step:
Biopsy showing intact epithelium and immunofluorescence lights up only the basement membrane
Tx:
- Widespread disease: Systemic Steroids
- Local disease: topical steroids
Patient with itchy vesicular lesion that looks like herpes on extensor regions of buttocks, (-) Nikolsky sign. The patient also has diarrhea, distension, weight loss.
Dx, next step, tx?
Dermatitis herpetiformis and celiac disease (IgA deposition on the dermis causing enlargement of papillae)
Next step:
• Anti-transglutaminase and anti-endomysial
• EGD and Bx of small bowel
Tx:
- Dapsone for symptomatic relief.
- Remove gluten from diet (wheat, rye (centeno), oat, barley (cebada))
Patient Blisters in sun-exposed areas (e.g., dorsum of hands), and Hypertrichosis.
Dx, next step, tx?
Porphyria Cutanea Tarda
Next step:
Uranalysis: Coral red urine under wood’s lamp
Tx: No sun exposure
Porphyria Cutanea Tarda associated with?
May not manifest until:
- HCV
- Hemochromatosis
- Oral contraceptive pills (OCP)
Patient with Rash + scales + flakes in hair areas (e.g, scalp, and eyebrows). Dx and tx?
Seborrheic dermatitis
Tx: Selenium shampoo
Patient with erythematous patches, symmetric silver scales that bleeds when picked in extensor surfaces and Gluteal fold. On physical you notice small holes in nails and separation of nail from the nail bed.
Dx and tx?
Psoriasis
Tx:
- 1st: UV light
- 2nd: topical steroids
Patient with hx of lymphoma who now has erythematous patches, symmetric silver scales that bleeds when picked in extensor surfaces and Gluteal fold. On physical you notice small holes in nails and separation of nail from the nail bed.
Next step?
Bx the lesions
Patient with erythematous patches, symmetric silver scales that bleeds when picked in extensor surfaces andgGluteal fold. On physical you notice small holes in nails and separation of nail from the nail bed. In addition, the patient has joint pain.
Dx and tx?
Psoriatic arthritis
For skin lesions:
- 1st: UV light
- 2nd: topical steroids
For joint pain:
- NSAIDs
- DMARDs (hydroxychloroquine, methotrexate)
- TNF-alfa-inhibitors (Etanercept) if severe disease
Patient with many flat, oval, salmon-coloured macules that have scales in the center without reaching the edge. Spare palms and soles.
Dx and tx?
Pityriasis Rosea
Tx: nothing; Self-limited disease (6 weeks)
Patient with many flat, oval, salmon-coloured macules that have scales in the center without reaching the edge. On physical you notice lesions on palms and soles as well.
Next step?
R/O syphilis and do a RPR
Patient who after the start of a new medication (ACE-i, thiazides, or loop diuretics) has intensely pruritic pink/purple flat-topped papules with a reticulated network of fine white lines.
Dx and tx?
Lichen Planus
Tx: topical steroids
Patient with chronic itchy symmetric lichenification (scaring) at the antecubital fossa, popliteal fossa and extensor. History of allergies, asthama, atopy.
Dx and tx?
Atopic dermatitis (eczema)
Tx:
- Avoid trigger
- Emulsions to alleviate itch
- Short-term topical steroids
Patient with erithematous itchy lesion in a finger with the shape of a ring.
Dx and tx?
Contact dermatitis (type IV hypersensitivity )
Tx:
- Avoid trigger
- Topical steroids for itch
Patient with heart failure and lowe limb edema who has erythema, brown discoloration, and scaling (flaking) of skin. It looks like bileteral celulitis.
Dx and tx?
Stasis dermatitis
Tx:
- Diuretics
- Compression stockings
- Elevation of legs
Healthcare professional with dry, erythematous hands. Dx and tx?
Hand dermatitis for excessive hand washing.
Tx:
- Stop excessive hand washing
- Protective gloves
- Avoid harsh soaps
Patient who after a bee sting has annular, blanching red papule of varying size that blanches when pushed. BP is normal.
Dx and tx?
Urticaria (hives)
Tx:
- Avoid trigger
- Anti-histamines
- Steroids
Patient who after a bee sting has annular, blanching red papule of varying size that blanches when pushed. BP is low.
Dx and tx?
Urticaria (hives) + anaphylaxis
Tx:
- IM epinephrine first!
- Anti-histamines
- Steroids
Hospitalized patient who 14 days after the start of a new medication has a pink, morbilliform rash that is widespread, symmetric, and pruritic.
Dx and tx?
Drug reaction
Tx:
- Stop culprit drug
- Mild Sx: Diphenhydramine
- Severe sx: steroids
- If anaphylaxis–> IM epinephrine
Patient with rash or blister in the same one spot 24 hrs after the same drug every time it’s administered.
Dx and tx?
Fixed drug reaction (no contraindication to antibiotics)
Tx: Avoid the drug
Patient with target shaped lesions in knees, face, fingers, palms and soles.
Differential?
Syphilis
Lyme disease
Erythema multiforme
Patient who after initiating a drug (Sulfa, Anticonvulsants, NSAIDs, HIV meds, and PCN) has target shaped lesions in knees, face, fingers, palms and soles.
Dx and tx?
Erythema multiforme
Tx:
- Remove culprit drug
- Topical steroids
- Watch out for Steven-Johnson if mucosal invovement
Differential of widespread loss of sheets of skin and (+) Nikolsky Sign.
- Pemphigus vulgaris (30-50 y-o, no fever, blistering)
- Steven-Johnson Syndrome (< 10% of body surface; basal cell degeneration on Bx)
- Toxic Epidermal Necrolysis (> 30% of body surface; full-thickness epidermal necrosis on Bx)
- Staphylococcus Scalded Skin Syndrome (infant, fever, no mucosal involvement)
Patient with widespread loss of sheets of skin and (+) Nikolsky Sign after initiating a drug (Sulfa, Anticonvulsants, NSAIDs, HIV meds, and PCN).
< 10% of body surface
Basal cell degeneration on Bx
Mucosal invovement
Dx and tx?
Steven-Johnson Syndrome
Tx:
- Stop all meds (even steroids)
- Burn unit
Patient with widespread loss of sheets of skin and (+) Nikolsky Sign after initiating a drug (Sulfa, Anticonvulsants, NSAIDs, HIV meds, and PCN).
> 30% of body surface
Full-thickness epidermal necrosis on Bx
Mucosal invovement
Dx and tx?
Toxic Epidermal Necrolysis
Tx:
- Stop all meds (even steroids)
- Burn unit
5 y-o patient, with fever and sloughing of skin that stats in skin folds. No mucosal involvement.
Dx and tx?
Staphylococcus Scalded Skin Syndrome
Tx: Nafcillin
ABCDE in dermatology?
If only one positive--> Bx • Asymmetry • Borders (irregular) • Colour (mixed colours) • Diameter (> 5mm) • Evolution
Old patient with a Large, Greasy, Brown, Crusted lesion that hasn’t changed. Dx?
Seborrheic keratosis
Patient how is a farmer/construction worker/sailor who has an erythematous lesion with a sandpaper-like yellow scale.
Dx and next step and tx?
Actinic keratosis (pre-malignant lesion wich evolves into Bowen’s disease and then into squamous cell carcinoma)
Next step: Bx
Tx:
- Local ablation with cryosurgery
- 5 Fluorouracil (5-FU) cream for diffuse lesions
Patient how is a farmer/construction worker/sailor who has a fleshy, erythematous, and crusted or ulcerated lesion in lower lip. Dx and tx?
Squamous cell carcinoma
Tx: resection