NEET-PG 2024 - Dermatology Practice Questions

Q: A patient presents with skin lesions and erosions on the buccal mucosa. The immunofluorescence image is shown. What is the most likely diagnosis?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - The combination of **flaccid blisters/erosions** on the skin and **buccal mucosal lesions** is characteristic of pemphigus vulgaris. The image showing **intercellular IgG deposits** (a "chicken wire" pattern) in the epidermis confirms the diagnosis on immunofluorescence. - Pemphigus vulgaris is an **autoimmune blistering disease** caused by autoantibodies against **desmoglein 1 and 3**, leading to acantholysis (loss of cell adhesion) within the epidermis. *Bullous pemphigoid* - This condition typically presents with **tense bullae** that are less prone to rupture, and **mucosal involvement is rare**. - Immunofluorescence in bullous pemphigoid shows **linear IgG and C3 deposits at the dermoepidermal junction**, not an intercellular epidermal pattern. *Linear IgA disease* - Characterized by **linear IgA deposition along the basement membrane zone** on direct immunofluorescence. - Clinically, it presents with **blisters** that can be variable in appearance, but the pathognomonic immunofluorescence pattern is distinct. *Dermatitis herpetiformis* - Presents with very **pruritic vesicles and papules**, primarily on extensor surfaces, and is strongly associated with **celiac disease**. - Direct immunofluorescence reveals **granular IgA deposits in the dermal papillae**, which is distinct from the intercellular IgG pattern seen here.

Q: A child presents with multiple patchy areas of hair loss, scales, and itching. The sister also had similar lesions. What is the most likely diagnosis?

Tinea capitis. ***Tinea capitis*** - **Tinea capitis** presents with **patchy hair loss**, **scaling**, and **itching** on the scalp, which are classic signs of a fungal infection. - The fact that the sister also had similar lesions indicates a **contagious** condition, consistent with a **dermatophyte infection**. *Alopecia areata* - Characterized by **sudden, non-scarring hair loss** in circular or oval patches, often with no scaling or inflammation. - It is an **autoimmune condition** and typically not associated with itching or contagiousness amongst siblings. *Pediculosis capitis* - This condition involves an **infestation of head lice**, primarily causing **intense itching** of the scalp. - While it is contagious, it typically presents with **nits** (lice eggs) firmly attached to hair shafts and excoriations from scratching, rather than significant hair loss and scaling. *Pyoderma* - **Pyoderma** is a bacterial skin infection, often presenting as **pustules**, **crusts**, or **blisters** on the scalp. - While it can be contagious and cause discomfort, it is primarily characterized by purulent lesions and not the diffuse patchy hair loss and scaling seen in this case.

Q: A patient with multiple sexual exposures is diagnosed with gonorrhea. What is the appropriate treatment?

Ceftriaxone. ***Ceftriaxone*** - **Ceftriaxone** is the **first-line recommended treatment** for uncomplicated gonorrhea according to **CDC and WHO guidelines**. - Administered as a **single intramuscular injection (500 mg IM)**, it provides highly effective coverage against *Neisseria gonorrhoeae* with minimal resistance. - It works by inhibiting bacterial cell wall synthesis, and is the **gold standard therapy** for gonorrhea treatment. - For patients with multiple sexual exposures, empiric treatment for co-infection with *Chlamydia trachomatis* (doxycycline) should also be considered. *Cefixime* - **Cefixime** was previously used as an oral alternative but is **no longer recommended** as first-line therapy due to **increasing resistance** of *N. gonorrhoeae*. - The CDC removed cefixime from recommended regimens due to **inferior efficacy** compared to ceftriaxone and concerns about treatment failures. - While it is an oral cephalosporin, it is **not appropriate first-line therapy** for gonorrhea. *Doxycycline* - **Doxycycline** is commonly used to treat **co-infection with *Chlamydia trachomatis***, which frequently occurs alongside gonorrhea. - The typical regimen is **100 mg twice daily for 7 days** as adjunctive therapy. - However, doxycycline is **not effective as monotherapy for gonorrhea** and should not be used alone to treat *N. gonorrhoeae* infection. *Acyclovir* - **Acyclovir** is an **antiviral medication** used to treat **herpes simplex virus (HSV)** infections. - It works by inhibiting viral DNA replication and has **no activity against bacterial infections** like gonorrhea. - It would be completely ineffective against *Neisseria gonorrhoeae*.

Question 1

A patient presents with skin lesions and erosions on the buccal mucosa. The immunofluorescence image is shown. What is the most likely diagnosis?

Accepted Answer

Pemphigus vulgaris

Answer

Bullous pemphigoid

Answer

Linear IgA disease

Answer

Dermatitis herpetiformis

Question 2

A child presents with multiple patchy areas of hair loss, scales, and itching. The sister also had similar lesions. What is the most likely diagnosis?

Accepted Answer

Tinea capitis

Answer

Alopecia areata

Answer

Pediculosis capitis

Answer

Pyoderma

Question 3

A patient with multiple sexual exposures is diagnosed with gonorrhea. What is the appropriate treatment?

Accepted Answer

Ceftriaxone

Answer

Acyclovir

Answer

Cefixime

Answer

Doxycycline

NEET-PG 2024 — Dermatology