Question
A 57-year-old male presents with a facial rash. On examination, there are reddish-pink, mildly scaly, poorly demarcated patches affecting the nasolabial folds and adjacent facial creases.
Which systemic condition is most commonly linked with this dermatological finding?
a) Systemic lupus erythematosus
b) Chronic kidney disease with protein loss
c) Human immunodeficiency virus infection
d) Ankylosing spondylitis
e) Motor neuron disease
Answer:
Human immunodeficiency virus infection
Detailed Explanation:
The clinical description strongly suggests seborrhoeic dermatitis, a chronic inflammatory skin condition affecting sebum-rich areas such as:
- Nasolabial folds
- Scalp
- Eyebrows
- Beard region
- Ears
- Sternum
Key Clinical Features:
- Salmon-pink or erythematous plaques
- Fine scaling
- Ill-defined margins
- Symmetrical distribution
Pathophysiology:
- Thought to be due to an inflammatory reaction to Malassezia furfur (a commensal yeast)
- Increased sebum production + immune dysregulation
Important Associations:
- HIV infection (very strong association; often more severe and resistant)
- Parkinson’s disease (autonomic dysfunction → increased sebum)
Why HIV?
- Seborrhoeic dermatitis is more severe, widespread, and treatment-resistant in HIV patients
- Can be an early marker of immunosuppression
Why other options are incorrect:
- SLE: Malar rash spares nasolabial folds
- Nephrotic syndrome: No direct association
- Rheumatoid arthritis: No link
- MS: No association
Cheat Sheet (Exam-Oriented)
Seborrhoeic Dermatitis
- Cause: Malassezia + inflammation
- Sites: Sebum-rich areas (face, scalp, chest)
- Appearance: Salmon-pink, greasy scales
- Key clue: Nasolabial fold involvement
Associations:
- HIV (high-yield)
- Parkinson’s disease
Treatment:
- Scalp: Ketoconazole shampoo
- Face: Topical antifungals ± mild steroids
- Chronic, relapsing condition
Flash Cards
Q1: Which fungus is implicated in seborrhoeic dermatitis?
A: Malassezia furfur
Explanation: Lipophilic yeast causing inflammatory response
Q2: Which facial area involvement helps distinguish seborrhoeic dermatitis from SLE?
A: Nasolabial folds
Explanation: Involved in seborrhoeic dermatitis, spared in SLE
Q3: Which systemic disease causes severe seborrhoeic dermatitis?
A: HIV
Explanation: Immunosuppression worsens condition
Q4: What neurological disease is associated with seborrhoeic dermatitis?
A: Parkinson’s disease
Explanation: Increased sebum due to autonomic dysfunction
MCQs (High Difficulty)
MCQ 1:
A patient presents with greasy scales over the scalp and erythematous plaques over the nasolabial folds. Which mechanism best explains the condition?
a) Type III hypersensitivity
b) Autoimmune keratinocyte destruction
c) Immune response to commensal yeast
d) Deposition of immune complexes
e) T-cell mediated epidermal apoptosis
Answer: c
Explanation: Seborrhoeic dermatitis is due to inflammatory response to Malassezia yeast
MCQ 2:
Which of the following is FALSE regarding seborrhoeic dermatitis?
a) Commonly affects sebum-rich areas
b) Associated with Parkinson’s disease
c) Spares nasolabial folds
d) Linked with HIV infection
e) Caused partly by Malassezia species
Answer: c
Explanation: It involves nasolabial folds (key differentiator from SLE)
MCQ 3:
A patient with resistant seborrhoeic dermatitis should be screened for:
a) Hepatitis B
b) HIV infection
c) Tuberculosis
d) Thyroid disease
e) Sarcoidosis
Answer: b
Explanation: Severe/refractory disease suggests immunosuppression
MCQ 4:
Which of the following treatments is first-line for scalp involvement?
a) Oral antifungals
b) Topical tacrolimus
c) Ketoconazole shampoo
d) Systemic steroids
e) Methotrexate
Answer: c
Explanation: Antifungal shampoo targets Malassezia
MCQ 5:
Which neurological condition is classically associated with seborrhoeic dermatitis?
a) Multiple sclerosis
b) Parkinson’s disease
c) Myasthenia gravis
d) ALS
e) Huntington’s disease
Answer: b
Explanation: Increased sebum production due to autonomic dysfunction
Summary for Quick Exam Revision
Seborrhoeic dermatitis is a chronic inflammatory skin condition affecting sebum-rich areas such as the scalp, nasolabial folds, eyebrows, and chest, characterized by salmon-pink, scaly, ill-defined plaques. It is caused by an inflammatory reaction to Malassezia yeast and commonly presents with greasy scaling. A key diagnostic clue is involvement of the nasolabial folds, helping differentiate it from SLE, where these folds are spared. Strong associations include HIV infection, where the condition is more severe and resistant, and Parkinson’s disease due to autonomic dysfunction increasing sebum production. First-line treatment includes topical antifungals such as ketoconazole, with steroids used short-term if needed. The condition is chronic and relapsing, making recurrence common. Recognizing the association with HIV is critical, especially in atypical or severe cases.