Dermatology Quiz

WIKIQUIZ

Questions reviewed by:

Anette Loeffler DrMedVet, DVD, DipECVD, MRCVS Lecturer in Veterinary Dermatology

1

In flea allergic dermatitis (FAD) to what do animals become allergic to? Flea larvae Flea eggs Flea contact Antigens in flea saliva Antigens in flea dirt Please select an option Incorrect. Animals become allergic to the antigens in the flea saliva not the flea larvae. Flea larvae feed on skin debris, flea dirt and other organic matter. The antigens in flea saliva trigger a hypersensitivity reaction when the flea bites. FAD leads to papular dermatitis, secondary excoriations and alopecic nodules (uncommon) if chronic. WikiVet Article: Flea allergic dermatitis Incorrect. Animals become allergic to the antigens in the flea saliva not the flea eggs. Most eggs are laid on the host but quickly fall off into the environment. The antigens trigger a hypersensitivity reaction when the flea bites. FAD leads to papular dermatitis, secondary excoriations and alopecic nodules (uncommon) if chronic. WikiVet Article: Flea allergic dermatitis Incorrect. Animals become allergic to the antigens in the flea saliva not flea contact. The antigens trigger a hypersensitivity reaction when the flea bites. FAD leads to papular dermatitis, secondary excoriations and alopecic nodules (uncommon) if chronic. WikiVet Article: Flea allergic dermatitis Correct! Animals become allergic to the antigens in the flea saliva triggering a hypersensitivity reaction when the flea bites. FAD leads to papular dermatitis, secondary excoriations and alopecic nodules (uncommon) if chronic. WikiVet Article: Flea allergic dermatitis Incorrect. Animals become allergic to the antigens in the flea saliva not flea dirt triggering a hypersensitivity reaction when the flea bites. FAD leads to papular dermatitis, secondary excoriations and alopecic nodules (uncommon) if chronic. WikiVet Article: Flea allergic dermatitis

2

Which species of mite inhabits the hair follicle? Notoedres cynotis Sarcoptes scabiei Otodectes cynotis Chorioptes bovis Demodex canis Please select an option Incorrect. Notoedric mites are rare but very contagious. They start on the neck and ears and spread to the head, face and paws becoming generalised. The correct answer is Demodex canis, a normal inhabitant of hair follicles and sebaceous glands. There needs to be an increased number of immature mites to classify as infestation. It is a host-specific infection that occurs in dogs, cattle, sheep, goats, pigs, horses and cats. WikiVet Article: Mites Incorrect. Sarcoptes scabiei causes scabies, a highly contagious skin disease, which is seen mainly in pigs and dogs, also horses, cattle, sheep, goats and cats. It causes an intense pruritus due to hypersensitivity to mites burrowing through the stratum corneum. The correct answer is Demodex canis, a normal inhabitant of hair follicles and sebaceous glands. There needs to be an increased number of immature mites to classify as infestation. It is a host-specific infection that occurs in dogs, cattle, sheep, goats, pigs, horses and cats. WikiVet Article: Mites Incorrect. Otodectic mites are present in external ear canals of carnivores, and occasionally elsewhere. The correct answer is Demodex canis, a normal inhabitantsof hair follicles and sebaceous glands. There needs to be an increased number of immature mites to classify as infestation. It is a host-specific infection that occurs in dogs, cattle, sheep, goats, pigs, horses and cats. WikiVet Article: Mites Incorrect. Chorioptic mites are surface mites that infest cattle, horses and goats. Areas usually affected are the lower hind legs in horses and cattle, scrotum, perineum, tail, udder and thigh in cattle and lower hind legs, hindquarters and abdomen in goats. The correct answer is Demodex canis, a normal inhabitant of hair follicles and sebaceous glands. There needs to be an increased number of immature mites to classify as infestation. It is a host-specific infection that occurs in dogs, cattle, sheep, goats, pigs, horses and cats. WikiVet Article: Mites Correct! Demodicosis is caused by Demodex canis, a normal inhabitant of hair follicles and sebaceous glands. There needs to be an increased number of immature mites to classify as infestation. It is a host-specific infestation that occurs in dogs, cattle, sheep, goats, pigs, horses and cats. WikiVet Article: Mites

3

What is a common dermatological abnormality seen in hypothyroidism? Comedones Bilaterally symmetrical alopecia Poor wound healing Calcinosis cutis Retention of puppy coat Please select an option Incorrect. Comedones are typically a feature of hypoadrenocorticism, or Cushing's disease. The correct answeris that a common dermatological abnormality seen with hypothyroidism is bilaterally symmetrical alopecia, which may also be accompanied by mucin within the dermis causing dermal thickening. WikiVet Article: Endocrine. Correct! The bilaterally symmetrical alopecia seen in hypothyroidism may also be accompanied by mucin within the dermis causing dermal thickening. Bilaterally symmetrical alopecia is also seen in other endocrine disorders e.g. hyperadrenocorticism. WikiVet Article: Endocrine Incorrect. Poor wound healing is a feature of hyperadrenocortism, it is due protein catabolism and weakness. The correct answer is that a common dermatological abnormality seen in hypothyroidism is bilaterally symmetrical alopecia, which may also be accompanied by mucin within the dermis causing dermal thickening. WikiVet Article: Endocrine. Incorrect. Calcinosis cutis is a feature of hyperadrenocortism, it is collagen damage due to protein catabolism which allows the deposition of calcium in the skin. Calcium acts as a foreign body producing a granulomatous reaction. The correct answer is that a common dermatological abnormality seen in hypothyroidism is bilaterally symmetrical alopecia, which may also be accompanied by mucin within the dermis causing dermal thickening. WikiVet Article: Endocrine. Incorrect. Growth hormone deficiency (hyposomatotropism), i.e. pituitary dwarfism results in a retained puppy hair coat. If the conditon occurs in adults, the coat does not develop and a bilaterally symmetrical, non-pruritic alopecia occurs over areas of friction e.g. neck and trunk. The correct answer is that a common dermatological abnormality seen with hypothyroidism is bilaterally symmetrical alopecia, it may also be accompanied by mucin within the dermis causing dermal thickening. WikiVet Article: Endocrine.

4

Which fungus is a commensal of the external ear canal in many domestic species? Microsporum canis Trichosporon beigelii Curvularia geniculata Malassezia pachydermatis Candida spp. Please select an option Incorrect. Microsporum canis causes dermatophytosis, or ring worm in dogs and cats. It is an infection of the stratum corneum. The correct answer is Malassezia pachydermatis,a yeast which is normally present in external ear canal and skin, and which may proliferate and cause clinical infection, Malassezia dermatitis. WikiVet Article: mycoses Incorrect. During infection with Trichosporon beigelii, minute swellings of hair shaft occurs. The correct answer is Malassezia pachydermatis, a yeast which is normally present in external ear canal and skin, and which may proliferate and cause clinical infection, Malassezia dermatitis. WikiVet Article: mycoses Incorrect. Curvularia geniculata causes eumycotic mycetomas, seen in horses and dogs. It can also be caused by Madurella and Acremonium. It is a tumour-like enlargement of granulomatous inflammation. The correct answer is Malassezia pachydermatis, a yeast which is normally present in external ear canal and skin, and which may proliferate and cause clinical infection, Malassezia dermatitis. WikiVet Article: mycoses Correct! Malassezia pachydermatis is a yeast normally present in the external ear canal and skin, which may proliferate and cause clinical infection, Malassezia dermatitis. WikiVet Article: mycoses Incorrect. Candida spp, normally present on the skin and in the gastrointestinal tract cause candidiasis. It may cause symptoms in immunocompromised animals, usually lesions on mucous membranes and at mucocutaneous junctions. The correct answer is Malassezia pachydermatis, a yeast which is normally present in the external ear canal and skin, and may proliferate and cause clinical infection, Malassezia dermatitis. WikiVet Article: mycoses

5

What skin lesion may be caused by copper deficiency in cattle? Generalised scaling Alopecia, crusts and scales on face, neck and distal extremities and mucocutaneous junctions Yellow or orange nodules in subcutaneous tissue Circumscribed reddened papules and plaques, thick crusting and scaling, fissures along ventral abdomen and medial thighs Spectacle pattern of depigmentation around eyes Please select an option Incorrect. Generalised scaling is usually a feature of vitamin A deficiency, which is a condition most commonly seen in dogs. The correct answer is a pattern of depigmentation around eyes, the coat colour may also change from black to reddish. WikiVet Article: nutrition Incorrect. Zinc deficiency in ruminants produces alopecia, crusts and scales on face, neck and distal extremities and mucocutaneous junctions. The correct answer is a pattern of depigmentation around eyes, the coat colour may also change from black to reddish. WikiVet Article: nutrition Incorrect. Yellow or orange nodules indicates vitamin E deficiency. The correct answer is a pattern of depigmentation around eyes, the coat colour may also change from black to reddish. WikiVet Article: nutrition Incorrect.Circumscribed reddened papules and plaques, thick crusting and scaling, fissures along ventral abdomen and medial thighs tends to be a manifestation of Zinc deficiency in pigs. The correct answer is a pattern of depigmentation around eyes, the coat colour may also change from black to reddish. WikiVet Article: nutrition Correct! Copper deficiency in cattle results in a spectacle pattern of depigmentation around the eyes. The coat colour may also change from black to reddish brown. Black sheep develop bands of lighter colouring. WikiVet Article: nutrition

6	What word describes a solid elevation ofthe skin ‹1cm in diameter? Papule Plaque Nodule Macule Pustule Please select an option Correct! A papule is a solid elevation of the skin < 1cm in diameter. If it were

7

What is the typical distribution of skin lesions in contact dermatitis? Dry gangrene of the extremities Papules around the lumbosacral area and posterior thighs Single lesion on carpal, metacarpal, metatarsal or radial area Lesions on ventral abdomen, chest, paws and chin Facial fold, lip fold, vulval fold and tail fold Please select an option Incorrect. Fescue poisoning is seen grossly as dry gangrene of the extremities, similar to ergot poisoning. It is caused by excessive consumption of Festuca arudinacea. The correct answer is contact dermatitis, which results from exposure to chemicals, not an immunologic reaction. It grossly appears as erythematous patches and papules and occasionally vesicles distributed on any areas in contact with the irritant. This is often the ventral abdomen, chest, paws and chin, but this varies from dog to dog and depends on what the initiating agent is. WikiVet Article: Chemical damage Incorrect. Flea allergic dermatitis tends to cause this distribution of lesions, and should be suspected in any dog or cat with papules around its rump and tail area. The correct answer is contact dermatitis, which results from exposure to chemicals, not an immunologic reaction. It grossly appears as erythematous patches and papules and occasionally vesicles distributed on any areas in contact with the irritant. This is often the ventral abdomen, chest, paws and chin, but this varies from dog to dog and depends on what the initiating agent is. WikiVet Article: Chemical damage Incorrect. Acral lick dermatitis, also called lick granuloma is caused by physical not chemical damage. It mostly occurs in dogs due to constant licking or chewing. Areas most affected are carpal, metacarpal, metatarsal, radial or tibial areas, usually just a single lesion. The correct answer is contact dermatitis, which results from exposure to chemicals, not an immunologic reaction. It grossly appears as erythematous patches and papules and occasionally vesicles distributed on any areas in contact with the irritant. This is often the ventral abdomen, chest, paws and chin, but this varies from dog to dog and depends on what the initiating agent is. WikiVet Article: Chemical damage Correct! Contact dermatitis results from exposure to chemicals, not an immunologic reaction. It grossly appears as erythematous patches and papules and occasionally vesicles distributed on any areas in contact with the irritant. This is often the ventral abdomen, chest, paws and chin, but this varies from dog to dog and depends on what the initiating agent is. WikiVet Article: Chemical damage Incorrect. Intertrigo, also called skin fold dermatitis, develops due to irritation and bacteria in areas of skin friction and moisture. Areas commonly affected include the facial fold in brachycephalic breeds, lip fold, body fold, vulval fold and tail fold. The correct answer is contact dermatitis, which results from exposure to chemicals, not an immunologic reaction. It grossly appears as erythematous patches and papules and occasionally vesicles distributed on any areas in contact with the irritant. This is often the ventral abdomen, chest, paws and chin, but this varies from dog to dog and depends on what the initiating agent is. WikiVet Article: Chemical damage

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Which of the following conditions affecting the skin is a Type II immunological reaction? Systemic lupus erythematosus Flea bite hypersensitivity Pemphigus Atopy Urticaria Please select an option Incorrect. Systemic lupus is a type III reaction, complement fixing of immune complexes IgG or IgM. Complexes deposit in tissue, fix complement, cytokines and other factors attack neutrophils which release lysosomal enzymes, and activate complement and coagulation. Platelet aggregation leads to tissue damage.The correct answer is Pemphigus, a rare group of immune mediated, sterile pustular diseases, in which autoantibodies bind to desmosomal proteins leading to formation of vesicles. There are several types. WikiVet Article: immunological Incorrect. Flea bite hypersensitivity involves type I and type IV hypersensitivity reactions and cutaneous basophil hypersensitivity. It mainly affects the dorsolumbosacral area, abdomen, caudomedial thighs, flanks and the neck of cats. Secondary trauma is self-inflicted. The correct answer is Pemphigus, a rare group of immune mediated, sterile pustular diseases, in which autoantibodies bind to desmosomal proteins leading to formation of vesicles. There are several types. WikiVet Article: immunological Correct! In a cytotoxic reaction, IgG and IgM interact with antigens bound to cellular membranes, this often involves complement fixation leading to cellular damage. Pemphigus is a rare group of immune mediated, sterile pustular diseases, autoantibodies bind to desmosomal proteins leading to formation of vesicles. There are several types. WikiVet Article: immunological skin conditions. Incorrect. Atopy is a type I reaction, mediated by pharmacologically active substances from mast cells and basophils due to antigen-antibody (usually IgE) binding to receptors on those cells. Substances include histamine, serotonin, leukotrienes and prostaglandins. Skin becomes pruritic and erythematous. The correct answer is Pemphigus, a rare group of immune mediated, sterile pustular diseases, in which autoantibodies bind to desmosomal proteins leading to formation of vesicles. There are several types. WikiVet Article: immunological skin conditions. Incorrect. Urticaria is a type I reaction, mediated by pharmacologically active substances from mast cells and basophils due to antigen-antibody (usually IgE) binding to receptors on those cells. Substances include histamine, serotonin, leukotrienes and prostaglandins. Skin becomes pruritic and erythematous. n, leukotrienes and prostaglandins. Skin becomes pruritic and erythematous. The correct answer is Pemphigus, a rare group of immune mediated, sterile pustular diseases, in which autoantibodies bind to desmosomal proteins leading to formation of vesicles. There are several types. WikiVet Article: immunological skin conditions.