Papulosquamous and Eczematous Dermatoses

Question 1

Atopic Dermatitis

Answer 1

IgE mediated type I hypersensitivity rxn

• **Filaggrin deficiency**
• TH2 cell involvement : type of T-helper cell
• pruritus
• scaling, non-demarcated, FLEXOR Creases
• tx: topical steroid ointment
• long-term tx: topical calcineurin inhibitors
  
  • ​phototherapy narrow range UVB
• Dupilumab = inhibits cytokines, $$$ but works very well

Question 2

Answer 2

Dyshidrotic Eczema

• most common onset is <40 years
• triggers: sweating, emotional stress, warm and humid weather, metals
• ** sudden onset of pruritic clear, tapioca-like tense vesicles on the soles, palms, & fingers (the lateral digits) **
• Diagnosis: clinical
• tx: topical corticosteroid ointments preferred
  
  • will usually resolve spontaneously
  • oral corticosteroids for severe cases

Question 3

Answer 3

Nummular Eczema

• IgE mediated type I hypersensitivity rxn
• Filaggrin gene mutation
• sharply defined coin-shaped lesions
  
  • (especially on the dorsal surfaces of the hands, feet, and extensor surfaces)
• Diagnosis: clinical
• tx: topical corticosteroids
  
  • ​antihistamines for itching
  • topical calcineurin inhibitors

Question 4

Acute Contact Allergic/Irritant Dermatitis

Answer 4

Allergic: type IV hypersensitivity rxn; Irritant: non-immunologic rxn

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Question 5

Answer 5

Seborrheic dermatitis

• caused by increased sebaceous gland activity + hypersensitivity rxn to Malassezia furfur
• greasy appearance of erythematous plaques with fine white scales
• tx: SELENIUM SULFIDE
  
  • ​sodium sulfacetamide, zinc pyrithione
  • ketoconazole shampoo

Question 6

Guttate Psoriasis

Answer 6

• small, erythematous “tear-drop” papules with fine scales, discrete lesions and confluent plaques
• often appear after a strep pharyngitis infx
• tx: <3% = topical corticosteroids
  
  • 5-10% = phototherapy + refer to derm
  • >10% = phototherapy + consider systemic tx + refer to derm
    
    • methotrexate, retinoids, & biologic
  • With Joint involvement: Methotrexate + refer to derm or rheum

Question 7

Inverse Psoriasis

Answer 7

Lack Scales, most commonly seen in body folds

• tx: <3% = topical corticosteroids
  
  • 5-10% = phototherapy + refer to derm
  • >10% = phototherapy + consider systemic tx + refer to derm
    
    • methotrexate, retinoids, & biologic
  • With Joint involvement: Methotrexate + refer to derm or rheum

Question 8

Plaque Psoriasis

Answer 8

keratin hyperplasia due to stratum basale and stratum spinosum proliferation

• TH17-cell activation
• most common on extensor surfaces
• raised, well-demarcated, pink-red plaques or papules with thick silvery scales
• auspitz sign: punctate bleeding with removal of plaque or scale
• **can have joint involvement**
• tx: <3% = topical corticosteroids
  
  • 5-10% = phototherapy + refer to derm
  • >10% = phototherapy + consider systemic tx + refer to derm
    
    • methotrexate, retinoids, & biologic
  • With Joint involvement: Methotrexate + refer to derm or rheum

Question 9

Answer 9

Pityriasis rosea

• associated with viral infections (HHSV 6 or 7)
• usually seen in older children and young adults
• will often start with a herald patch (single, salmon-colored macule) on the trunk followed by a general exanthem 1-2 weeks later
  
  • smaller, very pruritic round or oval salmon-colored papules
  • CHRISTMAS TREE PATTERN
• tends to affect trunk and proximal extremities
• tx: self resolving in 6-12 weeks
  
  • for pruritus: antihistamines, topical corticosteroids or oatmeal baths

Question 10

Lichen Planus

Answer 10

Associated with Hep C

• purple, pruritic, polygonal pattern that usually affects the volar surfaces of the ankle and wrist
• diagnosis: clinical diagnosis
• tx: topical corticosteroids with occlusive dressing
• rash will usually resolve on its own in 8-12 months

Question 11

Answer 11

Granuloma Annulare

• benign chronic condition
• can be tender, NO SCALING, deep
• center of each ring may be depressed
• erythematous lesions are usually on the dorsal hands, feet, legs or fingers
• tx: corticosteroid
  
  • ​topical tacrolimus
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