Red Scaly Rashes

Question 1

Differential Diagnosis of red scaly rashes

Answer 1

• Psoriasis
• Pityriasis Rosea
• Syphilis
• Lichen Planus
• Tinea (mannum, corporis, dermatophytosis, capitis)
• Granuloma Annulare
• Mycosis Fungoides
• Tinea Versicolor
• Subacute Cutaneous Lupus
• Discoid Lupus
• Lupus scarring - lose pigment
• Drug Rashes - urticarial, morbilliform
• Erythema Multiforme
• Erythema Chronicum Migrans (Lyme)
• Eczema - irritant, dyshidrotic eczema(pompholyx) and Atopic Dermatitis
• eyelid dermatitis (eczema)
• eczema and secondary infection
• Scabies

Question 2

Characteristics of Psoriasis

Answer 2

• inflammatory papulosquamous disease
• pink, scaly, well-demarcated plaques
• many variants: guttate, pustular, inverse etc
• silvery white scale, nail pitting, arthritis
• strong genetic/familial association
• mimmicks many other diseases

Question 3

Characteristics of Pityriasis Rosea

Answer 3

• self-limited, usually asymptomatic, viral exanthem
• pink-salmon oval patches with thin scale
• central trunk
• herald patch
• significant clinical overlap with secondary syphilis

Question 4

Characteristics of syphilis

Answer 4

• multi-organ infection of T. pallidum
• primary chancre
• primary, secondary, tertiary stages
• congenital and neurosyphilis stages
• many variations, features, cutaneous and non-cutaneous

Question 5

Characteristics of lichen planus

Answer 5

inflammatory papulosquamous disease

• violaceous papules, with white lacy lines
• wickham’s striae
• variants: hypertrophic, genital, oral, lichen, planopilaris (hair), nail dystrophy

Question 6

Characteristics of tinea

Answer 6

• common fungal infection of skin, hair and nails
• pink to red annular patches, scaly, central clearing, may have pustules
• variants: based on location
• spreads with topical steroid use (incognito)
• mimics many skin diseases

Question 7

characteristics of granuloma annulare

Answer 7

non-infectious granulomatous disease

• annular patches and plaques, no scale
• dorsal hands and feet
• generalized variant
• often misdiagnosed as tinea

Question 8

characteristics of mycosis fungoides

Answer 8

• malignat infiltrative disease of the skin of lymphocytes
• red violaceous patches, plaques, nodules and ulcerations
• early disease looks like a benign scaly process
• ultimately may invade other organs

Question 9

Characteristics of tinea versicolor

Answer 9

• superficial fungal infection
• Malassezia furfur
• annular sclay patches, central chest and back
• variable color changes: pink, orange, brown, white or hypopigmented
• common and recurrent

Question 10

characteristics of cutaneous lupus

Answer 10

• immunologic and inflammatory skin disease
• has a systemic risk, not always progressive
• sun-exposed areas, malar cheeks, annular, discoid
• other variants: neonatal, tumid, panniculitis

Question 11

Characteristics of drugs rashes

Answer 11

• allergic, immunologic and inflammatory reaction to meds
• no unifying characteristics
• many variants from urticaria to necrolysis
• blistering usually implies systemic effects
• can be mild to life-threatening

Question 12

Characteristics of erythema multiforme

Answer 12

• immunologic reaction pattern
• many triggers, meds and infections most common
• sulfa drugs and herpes simplex - common
• targetoid lesions on palms and soles
• mucosa may be involved
• minor and major variants
• many be a continuum to more worrisome inflammatory reactions

Question 13

Characteristics of erythema chronicum migrans

Answer 13

infection with borrelia burgdoferi, from deer tick bite

• bright red, blanchable, expanding macule
• target-like or bull’s eye shape
• may be asymptomatic to warm
• central clearing, may have a blue hue centrally
• long-standing infection may show multiple bulls-eye lesions

Question 14

Characteristics of eczema (dermatitis)

Answer 14

• very common inflammatory process
• spngiosis is the unifying histologic finding
• pink, scaly, very pruritic patches
• can be localized or diffuse
• many causes: contact allergy, irritant, atopic

Question 15

Characteristics of scabies

Answer 15

• infestations of the Sarcoptes scabiei mite
• pink pruritic papules and vesicles
• linear burrow
• almost always some other household member with pruritis or overt infection
• can be secondarily infected, bacteria, staph
• norwegian variant: crusted, overwhelming infestation