Lecture 4

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What typically triggers the spontaneous resolution of molluscum lesions?

Removal by scraping

Strengthening of the immune system (correct)

Exposure to liquid nitrogen

Application of topical treatments

Which HPV type is primarily associated with causing plantar warts?

HPV 3

HPV 1 (correct)

HPV 2

HPV 16

What is the hallmark characteristic of warts?

Rough, verrucous surface with black dots (correct)

Presence of clear fluid sacs

Smooth surface with no pigmentation

Large, scaly patches without pigmentation

Which treatment methods are effective for periungual warts?

Salicylic acid and liquid nitrogen Signup and view all the answers

Which of the following HPV proteins is known to degrade p53?

E6 Signup and view all the answers

What does the presence of black dots under a wart indicate?

Thrombosed capillaries Signup and view all the answers

Why can treating periungual warts be particularly difficult?

Potential to damage the fingernail Signup and view all the answers

What role do the early HPV proteins E6 and E7 play in the context of the virus?

They promote excessive proliferation of keratinocytes Signup and view all the answers

What is the most common causative organism of tinea capitis?

Trichophyton tonsurans Signup and view all the answers

Which of the following statements about tinea corporis is correct?

It presents as a red, scaly ring with central clearing. Signup and view all the answers

Which of the following best describes the scaling seen in tinea infections?

It serves as a defense mechanism against the infection. Signup and view all the answers

In darkly pigmented children, tinea corporis may show which of the following changes?

Hypopigmentation or hyperpigmentation Signup and view all the answers

What type of fungi causes both tinea capitis and tinea corporis?

Dermatophytes Signup and view all the answers

Which area of the body is typically NOT affected by tinea corporis?

Palms Signup and view all the answers

What is the primary method used to diagnose tinea infections?

Potassium hydroxide preparations Signup and view all the answers

The ring shape seen in tinea corporis is primarily due to which phenomenon?

Shedding of the stratum corneum Signup and view all the answers

What is the primary cause of varicella?

Varicella zoster virus Signup and view all the answers

What distinguishes varicella from smallpox regarding the appearance of lesions?

Lesions in varicella appear in different stages of development. Signup and view all the answers

What is a common method of transmission for lice?

Head-to-head contact Signup and view all the answers

Which treatment can significantly lessen the severity of varicella if administered early?

Antiviral medications Signup and view all the answers

How long can it take for hypersensitivity to lice saliva to develop?

Up to 6 weeks Signup and view all the answers

What is the characteristic feature of adult lice when identified?

They are occasionally seen and mobile. Signup and view all the answers

Within how many hours must varicella immune-globulin be administered after exposure for it to be effective?

96 hours Signup and view all the answers

What is a potential outcome for individuals immunized against varicella who still contract the disease?

They will typically experience milder disease. Signup and view all the answers

What is the characteristic appearance of the rash associated with Fifth Disease?

Bright red macular erythema on the cheeks Signup and view all the answers

Which virus is primarily responsible for causing Roseola?

Human herpesvirus 6 (HHV6) Signup and view all the answers

What triggers the appearance of the rash in Fifth Disease?

The immune response against the virus Signup and view all the answers

In what timeframe does the generalized rash of Fifth Disease typically last?

1-4 weeks Signup and view all the answers

How does Varicella often begin before the rash appears?

With a prodrome of low-grade fever and malaise Signup and view all the answers

Which group is primarily affected by Fifth Disease?

School-aged children Signup and view all the answers

What precaution is important for individuals with compromised hematopoietic function when infected with parvovirus B19?

They may develop significant anemia. Signup and view all the answers

What is a common treatment for managing high fevers in roseola?

Acetaminophen Signup and view all the answers

What is the recommended strategy for treating nits after the initial treatment?

Retreatment is recommended after one week. Signup and view all the answers

Which area is most commonly involved in atopic dermatitis in older children?

Antecubital fossae Signup and view all the answers

What is a common finding associated with chronic rubbing in periocular areas due to atopic dermatitis?

Periocular hyperpigmentation Signup and view all the answers

Which treatment is often avoided for periocular atopic dermatitis due to potential side effects?

Topical steroids Signup and view all the answers

What characteristic change is observed in the rash of atopic dermatitis as children age?

It develops more scaling and skin thickening. Signup and view all the answers

What is keratosis pilaris, as described in the context of atopic dermatitis?

Small hyperkeratotic papules at hair-follicle orifices Signup and view all the answers

What are the remnants that remain attached to the hairshaft after treatment for lice?

Nits (shells) Signup and view all the answers

What is the typical appearance of atopic dermatitis lesions in older children?

Dry and hyperpigmented Signup and view all the answers

What is the typical presentation of Henoch-Schonlein Purpura (HSP)?

Purpuric papules on legs and buttocks Signup and view all the answers

Which of the following treatments is used for pityriasis alba?

Moisturization and mild topical steroid Signup and view all the answers

Which complication can occur in cases of severe gastrointestinal manifestations of HSP?

Intestinal perforation Signup and view all the answers

What is the main finding observed in most cases of Henoch-Schonlein Purpura?

Palpable purpura Signup and view all the answers

Which condition is most often treated with milder topical acids such as lactic acid?

Keratosis pilaris Signup and view all the answers

What is the general duration of symptoms for Henoch-Schonlein Purpura?

1-6 months Signup and view all the answers

Which of the following statements about Henoch-Schonlein Purpura is correct?

It can be associated with respiratory infections. Signup and view all the answers

What long-term monitoring is recommended for patients after resolution of Henoch-Schonlein Purpura?

Renal function tests every six months Signup and view all the answers

Study Notes

Tinea Capitis and Tinea Corporis

Tinea corporis (ringworm of the body) is common in all races, and presents as a red, scaly ring with central clearing, sometimes with hyper/hypopigmentation in darker skin tones. It is not typically itchy or painful.
Tinea capitis (ringworm of the scalp) is relatively common in African-American and Hispanic children, and is more common than in adults. It typically involves hair loss with scaling on the scalp, and may have some erythema and pustules. Some cases can be itchy or painful.
Causative organisms:
- Tinea corporis: Trichophyton rubrum, Microsporum canis, and Trichophyton mentagrophytes.
- Tinea capitis: Trichophyton tonsurans.
Both conditions are caused by dermatophytes, fungi that digest keratin, affecting stratum corneum, hair, and/or nails.
Infections can be anthropophilic (human reservoir), zoophilic (animal reservoir), or geophilic (soil reservoir).
The scaling of the rash is a defense mechanism. Stratum corneum sheds faster than the organism can proliferate, removing the infection from the skin. The clearing in the center of the rash shows this removal.
Diagnosis: Potassium hydroxide (KOH) preparations or fungal cultures.
Treatment: Azoles (ketoconazole, miconazole, etc) inhibit fungal growth; allylamine (e.g., terbinafine) inhibits squalene epoxidase, which is an alternative treatment.

Molluscum Contagiosum

Extremely common in children. More common in those with atopic dermatitis.
Presents as small (1-3 mm), shiny, skin-colored papules with a central dimple. Lesions can appear anywhere on the body, and can grow large in immunocompromised individuals.
Caused by a DNA virus (poxvirus).
Transmitted through contact with skin lesions, or through shared objects.
Usually resolves spontaneously, but treatment includes scraping, salicylic acid, liquid nitrogen, or imiquimod.

Warts

Caused by human papillomaviruses (HPVs).
Various types of HPV cause different types of warts (e.g., plantar, periungual, "flat").
HPV proteins (L1, L2, E5, E6, E7) hijack cellular proliferation, inactivating normal regulatory proteins (p53 and retinoblastoma). This allows for excessive proliferation of keratinocytes.
Diagnosis is generally visual.
Treatments include salicylic acid and liquid nitrogen.

Periungual Warts

Warts near fingernails are common in children.
Characterized by a rough, "verrucous" surface with black dots (thrombosed capillaries) beneath.
Treatment approaches are similar to warts in other locations.

Pyogenic Granuloma

Red, moist nodules that often result from minor trauma.
Characterized by excessive wound healing response.
Typically treated with surgical removal and cauterization to prevent recurrence.

Hand-Foot-Mouth Disease (HFMD) and Herpangina

Caused by picornaviruses (e.g., Coxsackievirus A16).
HFMD presents with vesicles or pustules (often on hands and feet) and oral erosions (typically in mouth).
Herpangina involves only oral erosions.
Typically resolves spontaneously.

Viral Exanthems

Viral rashes are common, typically non-specific, presenting as widespread erythematous papules/papules, and urticarial lesions, with fever and possible malaise (general unwell feelings).
Often caused by enteroviruses.
Diagnoses based on clinical presentation.
Treatment consists of supportive care for symptomatic relief.

Papular Acrodermatitis of Childhood (Gianotti-Crosti)

Symmetric, monomorphic pink papules (bumps).
Typically on face, buttocks, and extensor surfaces of extremities.
Often occurs in children during spring/summer.
May be associated with viral infections.
Typically resolves without treatment.

Roseola Infantum

Characterized by a high fever for several days, followed by a non-specific rash of pink macules and papules.
Caused by HHV6 and HHV7.
Typically resolves spontaneously.

Unilateral Thoracic Exanthem (UTE)

Non-specific rash localized to one axilla or flank, but often spreads to the opposite.
Etiology is believed to be viral but not yet isolated.
Self-limiting with resolution within 1-2 months.

Varicella (Chickenpox)

Characterized by a widespread eruption of small vesicles on erythematous bases.
Caused by varicella-zoster virus (VZV), transmitted via respiratory droplets.
Usually resolves spontaneously.

Pediculosis Capitis (Head Lice)

Infestation of parasites (lice) on the head, characterized by intense itching.
Female lice lay eggs (nits) that attach to hair shafts.
Diagnosed by visual inspection; may have mobile lice or nits.
Treated with topical permethrin, Malathion, or oral ivermectin.

Henoch-Schönlein Purpura (HSP)

A type of vasculitis characterized by palpable purpura (reddish/purple spots) on the legs and buttocks, often triggered by an upper respiratory infection.
Symptoms can range from mild (mild skin rash and/or GI distress) to potentially serious (kidney involvement or GI distress such as bloody stools or abdominal pain).
Treat with supportive care for mild cases. More serious cases, require potentially oral steroids.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on Tinea capitis and Tinea corporis, two common fungal infections. This quiz covers the characteristics, causative organisms, and transmission of these conditions. Explore the differences in presentation and demographics associated with each type.