📚 Question Bank

The given clinical scenario with 'spaghetti and meatballs' appearance on the KOH mount is suggestive of pityriasis versicolor.

It is a mild, chronic infection of the skin most commonly caused by the lipophilic fungus Malassezia globosa. It may also be caused by M. furfur and M. sympodialis.

The KOH mount reveals fungal hyphae that are short and thick (like spaghetti or banana) and a large number of variously sized spores (like meatballs or grapes) referred to as 'spaghetti amp; meatballs' or 'bananas amp; grapes'.

Option A: Pityriasis alba is not a fungal infection, associated with eczema.

Option C: In tinea corporis infection, microconidia and macroconidia are seen under a KOH mount.

Option D: In candidiasis, spores and pseudohyphae of candida are seen in the KOH mount.

The above clinical scenario and image are suggestive of tinea nigra (pityriasis nigra). It is a rare superficial fungal infection caused by Hortaea werneckii.

The infection occurs by direct inoculation through the skin. It causes deeply pigmented, macular, non-scaly patches commonly on palms.

First-line treatment is topical azole creams such as econazole and ketoconazole.

The image below shows a microscopic image of tinea nigra, with pigmented filaments with conidia.

Option B: Malassezia globosa causes tinea versicolor. Option C: Fusarium causes mycotoxicosis.

Option D: Piedraia hortae causes black piedra.

The given image shows multiple hypopigmented macules and patches with fine scales

(branny/furfuraceous) suggestive of tinea versicolor (pityriasis versicolor).

Hypopigmentation is due to azelaic acid produced by Malassezia species that causes competitive inhibition of tyrosinase and a direct cytotoxic effect on hyperactive melanocytes.

Under Wood's lamp examination, lesions show a pale yellow fluorescence.

Besnier's sign (coup d'ongle sign or scratch sign or stroke of the nail): When the fine scales are not visible, an important diagnostic clue may be the loosening of barely perceptible scales with a fingernail, which is called the scratch sign. The most commonly affected site is the upper trunk.

Relapse is very common. First-line treatment:

• Topical azoles twice daily for 2–3 weeks
• Terbinafine 1 cream twice daily for 2–3 weeks
• Ketoconazole shampoo twice weekly for 2-3 weeks
• 2.5 selenium shampoo alternative days for 2-3 weeks

Second-line treatment: Oral itraconazole, 200 mg daily for 5 days

The image below shows the pale yellow fluorescence of Tinea versicolor under Wood's lamp.

The hard black nodules over the scalp hair are suggestive of black piedra. It is a fungal infection of the hair shafts caused by Piedraia hortae.

The fungus forms hard, dark, gritty, and superficial nodules on the hair shafts. As the fungus grows into the hair shaft, the hair may fracture easily. It produces sexual spores in its parasitic

phase. Treatment:

• Shaving or cutting hair (prevents recurrence also)
• Benzoic acid ointment is used.

Option B: Trichosporon beigelli causes white piedra or trichosporosis nodosa. Option C: Corynebacterium tenuis causes trichomycosis axillaris.

Option D: Trichophyton tonsurans causes mainly tinea capitis.

The images below show black piedra infected hair mounted in 30 KOH and the appearance of hair strands, respectively. The dark nodules are formed of dematiaceous hyphae cemented together to form a hard mass.

The images given below show white piedra. Superficial, soft, white, grey, or brown nodules can be seen.

The above image showing a single, intensely pruritic lesion with sharp margins and central resolution is suggestive of tinea corporis.

Central resolution is a frequent but not exclusive finding. Multiple lesions may be present.

Option B: Pityriasis rubra pilaris is a salmon-red dry scaly plaque with a nutmeg grater appearance.

Option C: Pityriasis versicolor presents as hypo or hyperpigmented macules with fine scaling. Option D: Piedra has black or white nodules present superficially on the hair shaft.

Dermatophytes infect and survive only in the dead keratin layers of skin (stratum corneum), hair and nails as they are keratinophillic.

The image shows a well-circumscribed, annular plaque in the groin region which is characteristic of tinea cruris. Tinea cruris is a dermatophytosis. Trichophyton, Microsporum and Epidermophyton are dermatophytes whereas Aspergillus is not.

Dermatophytes include 3 genera:

• Trichophyton species infect skin, hair, and nails and include T. rubrum, T. mentagrophytes, T.
• tonsurans, T. schoenleinii, and T. violaceum.
• Microsporum contains M. gypseum, M. canis, and M. nanum. These infect only hair and skin

(not nails).

• Floccosum is the only species in the genus Epidermophyton, It infects only skin and nails (not hair).

Aspergillus spp. produce large necrotic lesions like ecthyma gangrenosum, and sometimes small papules and cold abscesses.

The above image shows numerous fungal spores within the hair shaft suggestive of endothrix type of tinea capitis, which is caused by Trichophyton tonsurans.

Tinea capitis is of four types:

Type of Infection

Endothrix (infection inside s haft)

Ectothrix (infection outside s haft)

Favus Kerion

Causative fungus

Trichophyton tonsuransT.vio laceumT. schoenleiniiT.yaou ndeiT. soudanense

Microsporum audouiniiM.ca nisM.equinumM.ferrugineu m

T. schoenleinii

T. verrucosumT. mentagroph ytes

The above image shows an inflammatory mass with thick crusting and matting of hair which is suggestive of a kerion.

Kerion is a severe inflammatory type of tinea capitis. The most common causative organisms of kerion are T. verrucosum and T. mentagrophytes. In severe cases, there may be pus along with sinus formation.

Option A: Favus is characterized by the presence of yellowish, cupshaped crusts known as scutula that develop around hair follicles.

Option B: Ectothrix is a mild inflammatory type in which dull grey coated broken hairs are seen.

Option D: Endothrix is a non-inflammatory type in which black dots form around swollen hair shafts.

Note: Scarring alopecia is seen in favus and kerion while non-scarring alopecia is seen in ectothrix and endothrix.

The given clinical scenario depicting a young child with patchy hair loss and the image showing black dots is suggestive of endothrix type of tinea capitis.

Tinea capitis is a dermatophyte infection primarily occurring in children. Clinical features of tinea capitis are patchy hair loss, scaling, tender lymphadenopathy, and in severe cases, there might be pustules and crusting of the affected area along with sinus formation.

The clinical variants of tinea capitis are:

• Endothrix - a non-inflammatory type in which multiple black dots are present within the areas of alopecia. It is most commonly caused by T. tonsurans and T. violaceum.
• Ectothrix -a mild inflammatory type in which single or multiple scaly patches with hair loss are seen. Microsporum audouinii, M.canis, M.equinnum, and M.ferrugineum cause ectothrix infection.
• Kerion -a severe inflammatory type that presents with an inflammatory mass with thick crusting and matting of hair with pus and sinus formation. It is commonly caused by T.
• verrucosum and T. mentagrophytes.
• Favus - is characterized by the presence of yellowish, cupshaped crusts known as scutula that develop around hair follicles. It is caused by T. schoenleinii

Treatment:

• Terbinafine: lt;10 Kg- 62.5 mg; 10-20 kg - 125 mg; gt;20 kg- 250 mg, all given daily for 4
• weeks.
• Itraconazole: 2-4 mg/kg/day for 4-6 weeks.

Tinea incognito is an atypical clinical lesion of tinea, usually produced by incorrect treatment of fungal infection with a topical corticosteroid.

Steroids suppress inflammation without eliminating the fungus; so the typically raised margin is diminished, scaling is lost and inflammation reduces. Hence, diagnosis becomes difficult.

Pharmacological treatment of fungal tinea infection depends on the extent of the disease. Localized disease:

• Topical terbinafine twice daily for 2 weeks
• Topical azole once or twice daily for 2–4 weeks
• Widespread disease:
• First-line - oral terbinafine 250 mg/day 2–3 weeks or oral itraconazole 100 mg/day 2–4 weeks
• Second-line - oral griseofulvin 1 g/day for 4 weeks

The above image shows a scaly pruritic lesion of tinea pedis or ringworm of foot is most commonly caused by Trichophyton rubrum infections (70) followed by Trichophyton interdigitale infections (15), Epidermophyton floccosum infections (lt;10), and mixed infections (5).

Dhobi's itch/tinea cruris is an infection of the groin by a species of dermatophyte. It is commonly known as ringworm of the groin or eczema marginatum.

T. rubrum is the main cause; however, T. Interdigitale and E. floccosum also account for some cases.

The image shows a scaly pruritic lesion affecting the scalp hair, suggestive of tinea capitis. The drug of choice treatment for children in whom the cause of tinea capitis is unclear is griseofulvin. Terbinafine is the alternate first-line drug for adults.

Option A: Oral terbinafine is also used in the treatment of T. tonsurans tinea capitis in children, but usually used in adults.

Option C: Fluconazole is more effective in the treatment of M. canis compared to terbinafine. Option D: Selenium sulphide has only a supportive role in the treatment of tinea capitis.

The above image is suggestive of tinea faciei, a dermatophyte infection of the glabrous skin of the face (the mustache and beard areas of the adult male are excluded). It is diagnosed by KOH mount.

Trichophyton mentagrophytes and T.rubrum predominate, but T.tonsurans, M. audouinii, and M. canis are also common causes.

The above scenario is suggestive of tinea corporis and the slide showing smooth-walled

club-shaped macroconidia with absent microconidia is indicative of Epidermophyton species. Epidermophyton species infects skin and nails but not the hair.

The above scenario describes a dermatophytid (-id) reaction, a systemic reaction to fungal antigens during the infection or therapy.

An id reaction can be seen on the hands and sides of the fingers, but fungi cannot be demonstrated in these lesions.

The reactions may be vesicular, lichenoid, papulosquamous, or pustular. The lesions are extremely pruritic and tender. The onset can be accompanied by fever, anorexia, generalized adenopathy, spleen enlargement, and leukocytosis.

Although the eruptions are usually refractory to topical corticosteroids, they typically clear rapidly after treatment of the fungal infection. Secondary bacterial infections may occur.

Tinea unguium is a dermatophytic infection of the nail plate. Onychomycosis is a broad term for all fungal nail infections.

Trichophyton rubrum accounts for most cases.

It presents with yellowish discoloration, which spreads proximally as a streak in the nail. Later, subungual hyperkeratosis becomes prominent and spreads until the entire nail is affected.

Gradually, the entire nail becomes brittle and separated from its bed as a result of the piling up of subungual keratin.

Six distinct patterns of tinea unguium have been described.

• Distal and lateral subungual onychomycosis (DLSO) (most common)
• Superficial onychomycosis (SO)
• Proximal subungual onychomycosis
• Endonyx onychomycosis
• Totally dystrophic onychomycosis
• Mixed onychomycosis

Diagnosis is made by KOH mount examination of clippings or curettings that include dystrophic subungual debris.

The above image shows onychomycosis of toenails. The first-line treatment is oral terbinafine 250mg/day for 12 weeks.

Treatment of onychomycosis:

Second-line drug: Oral griseofulvin dose 1 g/day for 4–8 months (longer for toenails).

Topical treatment with amorolfine or ciclopirox olamine can be used in mild infections affecting the distal nail plate only or nonlinear superficial onychomycosis.

Finger nai ls

Toe nails

Oral terbinafine

250mg/day for 6 wee ks

250mg/day for 12 wee ks

Oral itraconazole

400mg/day for 1week, repeat ed every month for 2-3month s

400mg/day for 1week, repeat ed every month for 3-4 mont hs

Soreness and cracking at the angles of the mouth are seen in Perlèche. It is considered as an intertrigo where candida is the most common organism implicated.

It is also called angular stomatitis. It is a type of oral mucosal candidiasis. Nutritional status and mechanical factors (e.g. the depth of the fold), the presence of moisture from persistent salivation or licking the lips also contribute to stomatitis.

Chronic atrophic candidiasis presents with a red patch, not white. Candidiasis of the oral mucosal membranes is of the following types: Image: Chronic Atrophic Candidiasis

Type of Candidiasis

Acute pseudomembranous ca ndidiasis /Oral thrush /Chron ic pseudomembranous candi diasis

Acute erythematous candidia sis

Chronic erythematous candid iasis /Chronic atrophic candi diasis /Denture stomatitis

Chronic plaquelike candidia sis /Chronic hyperplastic can didiasis /Candida leukoplakia

Chronic nodular candidiasis

Angular cheilitis/Angular sto matitis/ Perlèche

Description

Sharply defined patch of crea my, crumbly, curdlike, whit e pseudomembraneHas an u nderlying erythematous base

Denuded, atrophic, erythema tous mucous membranesMos t common- dorsum ofthe ton gue

Affected areas show a variabl e bright red or dusky erythe maFairly sharply defined at t he margin of the denture

Very persistent, firm, irregul ar, white plaques occur in the mouthCommonly on the che ek or tongue

Tongue has a cobbled appear ance

Soreness at the angles of the mouth extending outwards in thefolds of the facial skin

The erythematous, non-scaly moist patches with tiny, superficial, white pustular satellite lesions are suggestive of candidal intertrigo.

Sites of infection:

• Between genital folds and groins
• Armpits
• Between the buttocks
• Inframammary fold (large and pendulous breasts)
• Under overhanging abdominal folds
• Umbilicus.
• Web spaces of toes, fingers

Marked maceration with a thick, white, horny layer is usually prominent. Soreness and itching are present.

The disease usually spreads beyond the area of contact, developing lesions with irregular edges and subcorneal pustules rupturing to give tiny erosions which lead to peeling of the stratum corneum.

Psoriasis, tinea corporis, and pityriasis rotunda have scaly lesions. The image below shows candidial intertrigo.

The above image shows the volcano sign seen in Oriental sore.

The lesion starts as a small non-tender papule, which enlarges in size and ulcerates in the centre. The border of the crusted ulcer often has an erythematous rim and is called a “volcano sign.”

It is also called cutaneous leishmaniasis or old world leishmaniasis, Kandahar sore, Lahore sore, or Delhi boil.

Causative organisms:

• Old world leishmaniasis: L. donovani, L.major, and L.tropica
• New world leishmaniasis: L. mexicana complex and L. braziliensis complex

The above image shows nodular lesions that have broken down to form draining sinuses with purulent discharge which is suggestive of mycetoma.

The nodules are painless and with time form papules and pustules which break down to form draining sinuses, with the discharge of granules. It is caused by various types of fungi (eumycetoma) or filamentous bacteria (actinomycetes).

The above image shows Medlar bodies that are suggestive of chromoblastomycosis.

Medlar bodies are golden-brown, thickwalled muriform or sclerotic cells in abscesses. They may also be found within giant cells.

Chromoblastomycosis is a chronic infection of the skin and subcutaneous tissue which is caused by pigmented fungi (Phialophora and Fonsecaea species). The lesions start as warty papules, slowly enlarge to form a hypertrophic plaque progressing to large hyperkeratotic masses over months to years. Satellite lesions are produced by scratching.