3.2 Papulosquamous, lichenoid, and eczematous dermatoses

Question 1

Pathogenic factors for psoriasis?

Answer 1

1. abnormal T cell activation
2. abnormal kearatninocytes - incrased mitotic activity, increasedinvolucrin in all layers
3. genetics

Question 2

Medication triggers for psoriasis?

Answer 2

Lithium, B blocker, antimalarials, ACEIs, NSAIDS, withdrawal of systemic steroids, G-CSF, interferon

Question 3

Three types of pustular psoriasis?

Answer 3

1. generalized ( von Zumbusch) - malaise, fever, pustules caused by hypocalcemia, pregnancy, steroid tapering
2. palmoplantar pustulosis - may be a/w SAPHO
3. acrodermatitis continua of Hallopeau - pustules limited to fingertip

Question 4

5 types of psoriatic arthritis?

Answer 4

1. asymmetric oligoarthritis (70%)
2. asymmetrical DIP arthritis (5-10%)
3. symmetrical polyarthritis (RA-like) (15%)
4. spondylitis and sacroilitis (5%)
5. arthritis mutilans (5%)

Question 5

Circinate balanitis may be presenting sign of what?

Answer 5

HIV

Question 6

What is keratoderma blenorrhagicum?

Answer 6

Thick plaques with pustules and erythema on plantar surfaces, sometimes seen with classic triad for reactive arthritis (urethritis, arthritis, conjunctivitis)

Question 7

5 types of PRP?

Answer 7

Type 1 and 2 in adults, III-V in kids
1 (classic): sudden onset of sx with duration 2-5 years
2 (atypical): about 5% of cases, slow onset with alopecia, localized lesions, and chronic course

Question 8

Etiology of LP?

Answer 8

Cell mediated autoimmune rxn to basal layer keratinocytes, may be idiopathic, drug-related, or infection related (HCV)

Question 9

Lichenoid keratosis? (BLK)

Answer 9

Likely due to inflammation of letigo, actinic keratosis, or SK - solitary lesion mimicking LP histologically

Question 10

Most important factor in development of GVHD?

Answer 10

Histocompatibility; can also occur after transfusion of unirradiated blood products or donor lymphocytes in setting of soid organ transplant

Question 11

Major features of acute GVHD?

Answer 11

1-3 weeks after transplantation, triad of dermatitis, enteritis with diarrhea, and hepatitis +/- high fever, conjunctival erythema. p/w maculopapular eruption which may coalesce into confluent erythema +/- erythroderma or bullae resembling TEN, 30-50% of pts with mod/severe GVHD die

Question 12

Major features of chronic GVHD?

Answer 12

4 months after transplant. Can arise from acute or can be denovo. Two types: lichenoid and sclerodermoid

Question 13

Contact dermatitis is divided into which categories?

Answer 13

1. Irritant contact dermatitis (80% of CD) - direct local cytotoxic effect of irritant on skin
2. Allergic contact dermatitis (20% of CD) - type IV DH to contact

Question 14

Irritant contact dermatitis divided into which categories?

Answer 14

1. Acute ICD - acute exposure, p/w pruritus and sharply localized erythema with vesicles, edematous papules; no distant spread
2. Chronic ICD - repeated exposure to mild irritants; p/w diffuse or localized but ill-defined scaly patches and plaques

Question 15

Allergic contact dermatitis divided into which categories? (need to do patch testing)

Answer 15

1. Acute ACD - 1-2 days after exposure, p/w pruritus, vesicles, weeping and erythema
2. Subacute ACD 0 eczematous scaly plaques or lichenification correlating to areas of contact with allergen