Non-Cancerous Skin Disorders

Question 1

Group of epidermal diseases with thickened stratum corneum but thin epidermis, impaired tonofilament formation, excessive cornification, and increased basal cell proliferation.

Answer 1

Ichthyoses

Question 2

Autosomal dominant and most common epidermal disease: caused by decreased of absent profilaggrin; marked by hyperkeratosis, small white scales, and a thin stratum granulosum.

Answer 2

Ichthyosis vulgaris

Question 3

Heritable epidermal disease characterized by steroid sulfatase deficiency and delayed desmosomal dissolution (persistent cohesion) of the stratum corneum, with a preserved granular layer.

Answer 3

X-linked ichthyosis

Question 4

Autosomal dominant epidermal disease caused by keratin tonofilament disassembly, leading to whorled, eosinophilic keratin filaments surrounding the nucleus, hyperkeratosis, and blistering.

Answer 4

Epidermolytic hyperkeratosis

Question 5

Autosomal recessive epidermal disease characterized by TGM1 (transglutaminase 1) mutations and defective lamellar body secretion; granular layer is normal or thickened.

Answer 5

Lamellar ichthyosis

Question 6

Autosomal dominant epidermal disease linked to ATP2A2 calcium pump defect that affects Ca-dependent desmosome assembly; characterized by mutlifocal papules and is also known as keratosis follicularis.

Answer 6

Darier disease

Question 7

Epidermal disease where a genetic predisposition + trauma leads to persistent hyperplasia/hyperproliferation and altered differentiation; seronegative arthritis can develop and is linked to HLA-B27

Answer 7

Psoriasis

Question 8

Epidermal disease featuring large, red, silvery-scaled plaques on the extensor surfaces with hyperplasia, hyperkeratosis, and parakeratosis (persistent nuclei); pinpoint bleeding can occur when plaques are removed.

Answer 8

Psoriasis

Question 9

In psoriasis, the Munro microabscesses in the stratum corneum, spongiform pustules of Kogoi, “squirting papillae” of capillary loops, and increased arachidonic acid and leukotriene B in the epidermis are all related to an excess of what inflammatory cells?

Answer 9

Neutrophils

Question 10

What epidermal disease is caused by autoantibodies (IgG) directed against keratinocyte membrane antigens (desmoglein 3)? What related disease involves IgG and desmoglein 1?

Answer 10

Pemphigus vulgaris; pemphigus foliaceus

Question 11

What autoimmune epidermal disease involves diminished epidermal cohesiveness, intraepidermal bullae, easily ruptured blisters, and tombstone cells following acantholysis?

Answer 11

Pemphigus vulgaris

Question 12

What basement membrane zone disease is usually noted at birth and features blisters that can range from minor to life-threatening?

Answer 12

Epidermolysis bullosa

Question 13

Name the 3 types of epidermolysis bullosa. How does the Kindler syndrome relate to these types?

Answer 13

Epidermolytic (EB simplex), junctional, or dermolytic (dystrophic);
Kindler syndrome displays a mix of these cleavage planes but also shows poikiloderma (mottled pigmentation) and photosensitivity

Question 14

What basement membrane zone disease is caused by autoantibodies (IgG) directed against basement membrane/lamina lucida antigens (BPAG1 and BPAG2)? It features eosinophil degranulation and tense blisters, but no acantholysis.

Answer 14

Bullous pemphigoid

Question 15

What basement membrane zone disease is caused by immune complex deposition following IgA-mediated gluten sensitivity? Neutrophils accumulate in intensely pruritic plaques and subepidermal vesicles on the extensor surfaces.

Answer 15

Dermatitis herpetiformis

Question 16

What self-limited basement membrane zone disease, characterized by “target” lesions, is often a reaction to a drug or infection? Name the more life-threatening version that can cause ulceration of the mucous membranes and internal organs.

Answer 16

Erythema multiforme minor; Stevens-Johnson syndrome is erythema multiforme major

Question 17

What basement membrane zone disease is caused by immune complex deposition and lymphocyte-induced cell injury, including basal keratinocyte injury and vacuolization? The systemic form may be brought on by sun exposure

Answer 17

Systemic lupus erythematosus

Question 18

Which form of SLE, limited to the skin, is ANA(-), has a thin epidermis and thick lamina densa, and features immune complexes mostly deep to the lamina densa?

Answer 18

Chronic cutaneous (discoid) LE

Question 19

Which form of SLE is common in young- to middle-aged white women, can spread to the musculoskeletal system and kidneys, and features edema of the papillary dermis and a thickened lamina densa but nothing deeper?

Answer 19

Subacute cutaneous LE

Question 20

Which form of SLE features a “butterfly” malar rash, maculopapular eruption that can spread t the kidneys and joints, and elevated ANA levels?

Answer 20

Acute systemic LE

Question 21

Bullous SLE involves subepidermal blisters (beneath the lamina densa) and is caused by autoantibodies against what molecule?

Answer 21

Against type VII collagen

Question 22

What basement membrane zone disease involves decreased epidermal turnover, melanophages (macrophages with ingested melanin), a dense infiltrate of lymphocytes and macrophages, and Wickham striae (white patches or streaks on oral mucous membranes)?

Answer 22

Lichen planus

Question 23

Urticaria and angioedema are vascular hypersensitivity reactions mediated by what immunoglobulin? Which one occurs in the deeper dermis/subcutis, and what form is associated with a C1-esterase inhibitor mutation?

Answer 23

IgE; angioedema; hereditary angioedema

Question 24

Cutaneous necrotizing vasculitis (a.k.a. allergic cutaneous vasculitis / leukocytoclastic vasculitis / hypersensitivity angiitis) is a vascular immune reaction characterized by what 2 observable features?

Answer 24

Neutrophil infiltration of vessel walls and palpable purpura (leukocytoclasia, or damage to neutrophils that leave dust-like nuclear remnants, may also be seen)

Question 25

What vascular skin reaction, a type of spongiotic (edematous) dermatitis, involves cell-mediated hypersensitivity to exogenous sensitizing agents (haptens/oleoresins)?

Answer 25

Allergic contact dermatitis

Question 26

In the sensitization phase of allergic contact dermatitis, what type of cell presents haptens to CD4 cells and make IL-1 to support T cell proliferation, in preparation for the elicitation phase?

Answer 26

Langerhans cells

Question 27

List 3 granulomatous skin lesions: one that is a response to indigestible antigens, one that primarily affects the lungs but can spread to the dermis and subcutis, and one that is characterized by “necrobiosis” from macrophage enzymes.

Answer 27

Granulomatous dermatitis; sarcoidosis; granuloma annulare

Question 28

What dermal connective tissue disease is characterized by hard, tense skin; an expressionless face; radial furrows around the mouth; Raynaud phenomenon, kidney and lung damage; collagen bundles in the dermis; and sweat ducts entrapped by fibrous tissue?

Answer 28

Scleroderma

Question 29

What inflammatory disorder of the panniculus/subcutis is a self-limited reaction to toxic and infectious agents that features non-suppurative, tender nodules on extensor surfaces (esp of the lower extremities and shins), and septal panniculitis that sometimes extends into the fat lobule?

Answer 29

Erythema nodosum

Question 30

What inflammatory disorder of the panniculus/subcutis presents with recurrent nodules or plaques on the legs, is often associated with Mycobacterium tuberculosis, and features lobular panniculitis secondary to vasculitis and ischemic necrosis of the fat lobule?

Answer 30

Erythema induratus

Question 31

What disease of the pilosebaceous (hair + sweat follicles) unit can be a response to Propionibacterium acnes or hormones, and features open and closed comedones called blackheads and whiteheads?

Answer 31

Acne vulgaris

Question 32

What impetigo sequelae occurs when organisms (Staph or Strep) invade deeper to form a necrotizing ulcerated lesion with neutrophils in the floor of the ulcer and in the dermis?

Answer 32

Ecthyma

Question 33

Dermatophytosis / tinea / ringworm is most commonly caused by what species?

Answer 33

Trichophyton rubrum

Question 34

The dermatophyte Malassezia furfur, which requires a moist and lipid-rich environment to thrive, can cause what disease marked by variably sized, pigmented, sharply demarcated macules with fine scales, predominantly on the upper trunk?

Answer 34

Tinea versicolor

Question 35

What transient, self-limited poxvirus infection, common among children and sexually active adults, is marked by firm, dome-shaped, smooth papules with central umbilication and cerrucous epidermal hyperplasia?

Answer 35

Molluscum contagiosum

Question 36

What organisms are the causes of scabies and pediculosis?

Answer 36

Mites (Sarcoptes scabei); lice