Fungal, Bacterial, Parasitic Skin Infection

Question 1

What are the three main genera of dermatophytes?

Answer 1

Trichophyton, Epidermophyton, Microsporum.

Question 2

What is the common name for dermatophyte infections?

Answer 2

Ringworm.

Question 3

What are the three modes of dermatophyte transmission?

Answer 3

Anthropophilic (human-to-human), Zoophilic (animal-to-human), Geophilic (soil-to-human).

Question 4

What is tinea corporis?

Answer 4

Ringworm of the body, presenting as itchy, scaly patches with central clearing.

Question 5

What is tinea cruris?

Answer 5

Fungal infection of the groin, more common in men, causing an itchy rash with a scaly border.

Question 6

What is tinea pedis?

Answer 6

Athlete’s foot, affecting the toe clefts with maceration, fissures, and scaling.

Question 7

What is tinea faciei?

Answer 7

Fungal infection of the face, often triggered by topical steroid use.

Question 8

What is tinea manuum?

Answer 8

Ringworm of the hands, causing diffuse scaling and thickened skin on the palms.

Question 9

What is tinea capitis?

Answer 9

Scalp ringworm, common in children, leading to hair loss and scaling.

Question 10

What is tinea unguium?

Answer 10

Fungal nail infection, causing thickened, discolored, brittle nails.

Question 11

How is dermatophyte infection diagnosed?

Answer 11

Skin scrapings, hair plucking, or nail clippings for microscopy and culture.

Question 12

What are first-line topical antifungals for dermatophyte infections?

Answer 12

Clotrimazole, miconazole, ketoconazole, terbinafine.

Question 13

When is oral antifungal therapy needed for dermatophyte infections?

Answer 13

For scalp, nail, or extensive skin involvement; drugs include itraconazole and fluconazole.

Question 14

What is candidiasis?

Answer 14

A yeast infection caused by Candida albicans, commonly affecting warm, moist areas.

Question 15

What are common presentations of candidiasis?

Answer 15

Napkin rash, genital infections, intertrigo, oral thrush.

Question 16

How is candidiasis diagnosed?

Answer 16

Microscopy and culture of skin swabs.

Question 17

What are treatments for candidiasis?

Answer 17

Topical antifungals (clotrimazole, ketoconazole) or systemic antifungals (itraconazole, fluconazole).

Question 18

What causes pityriasis versicolor?

Answer 18

Malassezia furfur, a commensal yeast.

Question 19

What are the clinical features of pityriasis versicolor?

Answer 19

Scaly oval macules on the upper trunk, usually hypopigmented or hyperpigmented.

Question 20

What is the diagnostic finding in pityriasis versicolor?

Answer 20

‘Spaghetti and meatballs’ appearance on microscopy.

Question 21

What are treatments for pityriasis versicolor?

Answer 21

Selenium sulfide or ketoconazole shampoo, topical or systemic azoles.

Question 22

Why does pityriasis versicolor often recur?

Answer 22

The causative yeast is a normal skin commensal.

Question 23

What is mycetoma?

Answer 23

A chronic fungal or bacterial infection affecting deep soft tissues and bones.

Question 24

What are the two types of mycetoma?

Answer 24

Eumycetoma (fungal) and actinomycetoma (bacterial).

Question 25

What is the common site for mycetoma?

Answer 25

Foot (Madura foot).

Question 26

How does mycetoma present?

Answer 26

Painless swelling, nodules, sinus tracts with discharge containing fungal grains.

Question 27

What are the colors of grains in mycetoma?

Answer 27

Black (eumycetoma), red/yellow (actinomycetoma), white (either).

Question 28

How is mycetoma diagnosed?

Answer 28

Microscopy, culture, and histopathology of grains in pus.

Question 29

What is the treatment for eumycetoma?

Answer 29

Itraconazole or ketoconazole for 6-12 months; surgery if needed.

Question 30

What is the treatment for actinomycetoma?

Answer 30

Penicillin or doxycycline.

Question 31

What are the two main forms of impetigo?

Answer 31

Bullous (Staphylococcus aureus) and non-bullous (Staph aureus or Streptococcus).

Question 32

What are predisposing factors for impetigo?

Answer 32

Skin abrasions, eczema, infestations.

Question 33

What is the treatment for mild impetigo?

Answer 33

Topical mupirocin or fusidic acid cream.

Question 34

What is the treatment for severe impetigo?

Answer 34

Oral antibiotics such as erythromycin or flucloxacillin.

Question 35

What is staphylococcal scalded skin syndrome (SSSS)?

Answer 35

A serious exfoliating condition in children due to epidermolytic toxins from Staph aureus.

Question 36

What are the clinical features of SSSS?

Answer 36

Fever, skin tenderness, erythema, blisters, and superficial erosions.

Question 37

What is the treatment for SSSS?

Answer 37

Systemic antibiotics (e.g., co-amoxiclav), intensive supportive care.

Question 38

What is toxic shock syndrome (TSS)?

Answer 38

A severe condition caused by Staphylococcus toxins, leading to fever, rash, circulatory collapse.

Question 39

What is the treatment for TSS?

Answer 39

Intensive supportive care and systemic antibiotics.

Question 40

What is folliculitis?

Answer 40

Superficial infection of hair follicles, often caused by Staphylococcus aureus.

Question 41

What is a furuncle?

Answer 41

A deep infection of a hair follicle (boil), usually with necrosis.

Question 42

What is a carbuncle?

Answer 42

A group of coalescing furuncles with deeper inflammation.

Question 43

What are common sites for furuncles and carbuncles?

Answer 43

Neck, buttocks, anogenital area.

Question 44

What is the treatment for severe furuncles and carbuncles?

Answer 44

Oral antibiotics (flucloxacillin) and incision and drainage if needed.

Question 45

What is cellulitis?

Answer 45

Bacterial infection of the subcutaneous tissue.

Question 46

What is erysipelas?

Answer 46

Infection of the dermis and upper subcutaneous tissue, often with defined edges.

Question 47

What are common causes of cellulitis and erysipelas?

Answer 47

Group A Streptococcus, Staphylococcus aureus.

Question 48

What are common complications of cellulitis?

Answer 48

Lymphoedema, septicemia, glomerulonephritis, cavernous sinus thrombosis.

Question 49

What is the treatment for mild cellulitis?

Answer 49

Oral antibiotics (e.g., flucloxacillin, penicillin).

Question 50

What is the treatment for severe cellulitis?

Answer 50

Intravenous antibiotics (e.g., benzylpenicillin with erythromycin).

Question 51

What causes scabies?

Answer 51

Sarcoptes scabiei mite infestation.

Question 52

How is scabies transmitted?

Answer 52

Close person-to-person contact.

Question 53

What are symptoms of scabies?

Answer 53

Intense pruritus (worse at night), burrows, vesicles, papules, pustules.

Question 54

What is the treatment for scabies?

Answer 54

Topical 5% permethrin, oral ivermectin.

Question 55

What is pediculosis?

Answer 55

Lice infestation of the scalp, body, or pubic area.

Question 56

What are the three types of lice affecting humans?

Answer 56

Head lice (Pediculus humanus capitis), body lice (Pediculus humanus corporis), pubic lice (Pthirus pubis).

Question 57

What are symptoms of pediculosis?

Answer 57

Itching, excoriations, swollen lymph nodes, conjunctivitis.

Question 58

What is the treatment for pediculosis?

Answer 58

Medications, mechanical removal (combing), washing clothing in insecticide.

Question 59

Who is at risk for body lice infestation?

Answer 59

Homeless or displaced individuals.

Question 60

How is pubic lice transmitted?

Answer 60

Sexual contact.