A 5-month-old child presented to the dermatology OPD with dryness along with white, fine scales on most parts of the body with sparing of face. The child was born at 39 weeks gestation by spontaneous vaginal delivery outside the hospital. On examination, fine, white scales were observed predominantly on the extensor surfaces of the limbs along with characteristic hyperlinearity of palms and accentuation of skin markings. Which of the following genes is most likely defective in the above condition:
Q82
All of the following are true about incontinentia pigmenti, except which of the following?
Q83
What is the most probable diagnosis of a child who presents with white umbilicated lesions on the face?
Q84
A child is born with a shiny, tight film covering the skin. What could be the possible diagnosis?
Q85
What condition is suggested by eyelid papules and a hoarse cry in a child?
Q86
A child with fever presents with multiple tender erythematous skin lesions, and on microscopic examination, the skin lesions are found to have neutrophilic infiltration in the dermis. What is the diagnosis?
Pediatric Dermatology Indian Medical PG Practice Questions and MCQs
Question 81: A 5-month-old child presented to the dermatology OPD with dryness along with white, fine scales on most parts of the body with sparing of face. The child was born at 39 weeks gestation by spontaneous vaginal delivery outside the hospital. On examination, fine, white scales were observed predominantly on the extensor surfaces of the limbs along with characteristic hyperlinearity of palms and accentuation of skin markings. Which of the following genes is most likely defective in the above condition:
A. Filaggrin (Correct Answer)
B. Desmoglein
C. Plakophilin
D. Plakoglobin
Explanation: ***Filaggrin***
- The clinical description of **fine, white scales**, **facial sparing**, **extensor surface involvement**, and **palmar hyperlinearity** is classic for **ichthyosis vulgaris**, the most common inherited disorder of keratinization.
- **Filaggrin (FLG)** gene mutations are the most common cause of ichthyosis vulgaris, leading to impaired formation of the skin barrier and loss of natural moisturizing factor.
- Typically presents between 3-12 months of age with xerosis and fine scaling.
- Key features include **facial sparing**, **flexural sparing**, and **prominent palmar/plantar markings**.
*Desmoglein*
- **Desmoglein 1** and **Desmoglein 3** are desmosomal cadherins associated with **pemphigus** (autoimmune blistering disorder).
- Desmoglein mutations do not cause ichthyotic scaling disorders.
- The clinical presentation of fine scaling with facial sparing is not consistent with pemphigus or other desmoglein-related conditions.
*Plakophilin*
- **Plakophilin-1** mutations cause **ectodermal dysplasia-skin fragility syndrome**, characterized by skin erosions, blistering, alopecia, and nail dystrophy.
- Does not present with generalized dry scaling or the pattern described in this case.
- Skin fragility and erosions are the hallmark, not ichthyosis.
*Plakoglobin*
- **Plakoglobin (JUP gene)** mutations cause **Naxos disease**, featuring the triad of arrhythmogenic right ventricular cardiomyopathy, woolly hair, and palmoplantar keratoderma.
- While palmoplantar involvement occurs, it is a focal keratoderma, not generalized fine scaling with facial sparing.
- Cardiac manifestations are the most serious feature of this condition.
Question 82: All of the following are true about incontinentia pigmenti, except which of the following?
A. Avascularity of peripheral retina
B. Primary skin abnormality
C. X-linked dominant
D. Ocular involvement is seen in almost 100% cases and is typically unilateral (Correct Answer)
Explanation: ***Ocular involvement is seen in almost 100% cases and is typically unilateral***
- **Ocular involvement** in incontinentia pigmenti is common, affecting about 30-35% of patients, not almost 100%
- When present, **ocular manifestations** are typically **bilateral**, not unilateral, though severity can vary between eyes
- This is the FALSE statement, making it the correct answer to this EXCEPT question
*Avascularity of peripheral retina*
- This is a TRUE statement and a common ophthalmological manifestation of **incontinentia pigmenti**
- **Peripheral retinal avascularity** leads to **ischemia** and can predispose to neovascularization, retinal detachment, and vision loss if not monitored
*Primary skin abnormality*
- This is a TRUE statement - **Incontinentia pigmenti** is primarily a neurocutaneous disorder
- Characteristic **skin lesions** are the most prominent feature and often the first sign
- The skin abnormalities evolve through distinct stages: **vesicular**, verrucous, hyperpigmented, and atrophic linear lesions following lines of Blaschko
*X-linked dominant*
- This is a TRUE statement - **Incontinentia pigmenti** is inherited in an **X-linked dominant pattern**
- Caused by mutations in the **NEMO gene** (IKBKG) located on the X chromosome
- Affected males often have more severe forms or are embryonically lethal; the condition predominantly affects females
Question 83: What is the most probable diagnosis of a child who presents with white umbilicated lesions on the face?
A. Herpes simplex infection
B. Molluscum contagiosum (Correct Answer)
C. Erythema toxicum neonatorum
D. Human papilloma virus infection
Explanation: ***Molluscum contagiosum***
- The description of **white, umbilicated lesions** is a classic presentation of **molluscum contagiosum**, a common viral skin infection in children.
- These lesions are typically **dome-shaped papules** with a central depression, often appearing on the face, trunk, and extremities.
*Herpes simplex infection*
- Herpes simplex typically presents as **vesicles on an erythematous base** that can later crust over, which is different from the described umbilicated lesions.
- It often causes **painful, recurrent outbreaks** and may be associated with systemic symptoms like fever.
*Erythema toxicum neonatorum*
- This is a benign rash seen in newborns, characterized by **blotchy red spots** with central papules or pustules, not white umbilicated lesions.
- It usually appears within the first few days of life and resolves spontaneously.
*Human papilloma virus infection*
- HPV typically causes **warts**, which are rough, verrucous papules, rather than smooth, umbilicated lesions.
- The appearance of warts can vary significantly but generally lacks the central umbilication seen in molluscum.
Question 84: A child is born with a shiny, tight film covering the skin. What could be the possible diagnosis?
A. Lamellar ichthyosis (Correct Answer)
B. X-linked ichthyosis
C. Ichthyosis vulgaris
D. Ichthyosis acquisita
Explanation: ***Lamellar ichthyosis***
- This condition is characterized by a **collodion membrane** at birth, which is a shiny, tight, and translucent film covering the entire skin surface.
- The collodion membrane typically sheds within the first few weeks of life, revealing **generalized scaling** and **erythema** beneath.
*X-linked ichthyosis*
- This type of ichthyosis is characterized by **large, dark, adherent scales**, especially on the neck, trunk, and extensor surfaces.
- It is caused by a deficiency of the enzyme **steroid sulfatase** and does not typically present as a collodion baby.
*Ichthyosis vulgaris*
- This condition usually presents in early childhood with **fine, whitish scales** predominantly on the extensor surfaces of the limbs, sparing the flexures.
- It does not present as a collodion baby and is often associated with **atopy**.
*Ichthyosis acquisita*
- This refers to ichthyosis that develops later in life due to an underlying systemic disease such as **lymphoma**, AIDS, or certain medications.
- It is not a congenital condition and therefore does not present at birth with a collodion membrane.
Question 85: What condition is suggested by eyelid papules and a hoarse cry in a child?
A. Croup
B. Lipoid proteinosis (Correct Answer)
C. Acrodermatitis enteropathica
D. Congenital syphilis
Explanation: ***Lipoid proteinosis***
- This condition is characterized by **hoarseness from infancy** due to deposition in the vocal cords and characteristic **beaded papules on the eyelids** (moniliform blepharosis).
- Also known as **Urbach-Wiethe disease**, it is a rare autosomal recessive disorder resulting from mutations in the **ECM1 gene**, leading to abnormal deposition of hyaline material in various tissues.
*Croup*
- Croup typically presents with a **barking cough** and **stridor**, often following a viral upper respiratory infection.
- It does not cause eyelid papules or chronic hoarseness from infancy, but rather acute respiratory distress.
*Acrodermatitis enteropathica*
- This is a rare autosomal recessive disorder of **zinc malabsorption**, leading to a classic triad of **dermatitis**, **diarrhea**, and **alopecia**.
- It does not involve eyelid papules or hoarseness as primary features.
*Congenital syphilis*
- Congenital syphilis can cause a wide range of manifestations, including skin rashes, bone abnormalities, and rhinitis ("snuffles"), but eyelid papules and chronic hoarseness are not typical presenting features.
- Diagnosis is usually confirmed by serological tests for syphilis.
Question 86: A child with fever presents with multiple tender erythematous skin lesions, and on microscopic examination, the skin lesions are found to have neutrophilic infiltration in the dermis. What is the diagnosis?
A. Sweet syndrome (Correct Answer)
B. Behcet's syndrome
C. Pyoderma gangrenosum
D. Leukemia cutis
Explanation: ***Sweet syndrome***
- **Sweet syndrome**, also known as acute febrile neutrophilic dermatosis, presents with **fever**, **tender erythematous plaques**, and a characteristic histology of **dense neutrophilic infiltrate in the dermis** without vasculitis.
- It is often triggered by **infection**, malignancy, or drugs and is more common in women, though it can occur in children.
*Behçet's syndrome*
- **Behçet's syndrome** is a multisystem vasculitis characterized by **recurrent oral and genital ulcers**, uveitis, and skin lesions such as erythema nodosum or papulopustular lesions, but not typically the specific neutrophilic dermatosis seen here.
- The hallmark is **recurrent aphthous ulceration**, which is not mentioned in the patient's presentation.
*Pyoderma gangrenosum*
- **Pyoderma gangrenosum** presents as rapidly enlarging, **painful necrotic ulcers** with undermined purplish borders, often associated with inflammatory bowel disease or hematological disorders.
- While it also involves neutrophilic infiltration, the clinical presentation of **tender erythematous plaques without ulceration** is not typical.
*Leukemia cutis*
- **Leukemia cutis** refers to infiltration of the skin by leukemic cells, which can present as papules, nodules, or plaques with **neutrophilic (myeloid) infiltration** on histology.
- However, it typically occurs in patients with **known or occult hematologic malignancy**, and the lesions are usually **non-tender** and may have a violaceous hue, unlike the tender erythematous plaques of Sweet syndrome.
- Sweet syndrome itself can be **paraneoplastic** and associated with myeloid malignancies, making the distinction important.
