26: Seborrheic Dermatitis Flashcards
What are the general features of seborrheic dermatitis?
Seborrheic dermatitis is characterized by erythematous, scaly patches on sebaceous gland-rich sites (scalp, face, upper trunk, intertriginous areas), ranging from mild pinkish scaling to solid adherent crusts. It is associated with itching and burning, leading to psychosocial distress, affects all races and ethnic groups with a worldwide distribution, and has a higher incidence and more severe forms in AIDS patients and individuals with certain neurologic conditions.
What is infantile seborrheic dermatitis and its characteristics?
Infantile seborrheic dermatitis affects babies as young as 2 weeks, with peak incidence at 3 months. It typically resolves within the first 6-12 months of life and presents as a nonpruritic skin eruption affecting the frontal or vertex areas of the scalp and central face, characterized by dry, thick, adherent, and flaking scale. It may be accompanied by an erythematous rash on intertriginous folds of the trunk and extremities, commonly known as ‘cradle cap’.
What are the clinical features of Leiner Disease?
Leiner Disease is characterized by desquamative erythroderma in infants, sparse hair, frequent loose stools, and failure to thrive. It is considered an umbrella phenotype rather than a single-disease entity, with congenital or acquired deficiencies of C3, C5, and phagocytic activity leading to defective opsonization of yeast and bacteria. Secondary bacterial infections can be life-threatening, and treatment includes IV hydration, temperature regulation, and antibiotics.
What is Pityriasis Amiantacea and its characteristics?
Pityriasis Amiantacea is an inflammatory condition of the scalp characterized by large plates of thick, silvering scale that are firmly adherent to both the scalp and hair tufts. It is also known as asbestos-like scalp and can be referred to as tinea asbestina, tinea amiantacea, keratosis follicularis amiantacea, and porrigo amiantacea.
What are the common clinical features of seborrheic dermatitis in adolescents and young adults?
Seborrheic dermatitis in adolescents and young adults typically presents as a chronic and relapsing pattern with erythematous, scaly patches on sebaceous gland-rich sites (scalp, face, upper trunk), itching and burning sensations, psychosocial distress due to cosmetic concerns, and increased activity of sebaceous glands due to hormonal effects.
How does infantile seborrheic dermatitis typically present in infants, and what is its expected course?
Infantile seborrheic dermatitis usually presents as a nonpruritic skin eruption affecting babies as young as 2 weeks, with peak incidence at 3 months, characterized by dry, thick, adherent, and flaking scale. It may be accompanied by an erythematous rash on intertriginous folds and is commonly referred to as ‘cradle cap’, typically resolving within the first 6-12 months of life.
What are the key differences between seborrheic dermatitis and Leiner disease in infants?
Key differences include:
Feature | Seborrheic Dermatitis | Leiner Disease |
|——————————-|——————————————-|———————————————|
| Presentation | Erythematous, scaly patches | Desquamative erythroderma |
| Hair | Normal or sparse hair | Sparse hair |
| Stool | Normal | Frequent loose stools |
| Failure to Thrive | Not typically present | Commonly present |
| Treatment | Topical treatments | IV hydration, antibiotics essential |
What are the clinical implications of pityriasis amiantacea, and how does it present?
Pityriasis amiantacea presents as an asbestos-like scalp condition, characterized by large plates of thick, silvering scale firmly adherent to both the scalp and hair tufts. Clinical implications include potential for secondary infections due to compromised skin integrity and may require specific treatments to manage inflammation and scaling.
What is the likely diagnosis for a 35-year-old male with erythematous, scaly patches on his scalp and face and a history of Parkinson’s disease?
The likely diagnosis is seborrheic dermatitis (SD). SD is more severe in patients with Parkinson’s disease due to facial immobility leading to sebum accumulation and potential neurotransmitter abnormalities.
What is the diagnosis for an infant with a nonpruritic skin eruption affecting the scalp and central areas of the face, accompanied by thick, adherent flaking scales?
The diagnosis is infantile seborrheic dermatitis (ISD). Unlike adult SD, ISD is nonpruritic, self-limited, and resolves by 6-12 months of age.
What are the common associations of Seborrheic Dermatitis (SD) with HIV and AIDS?
Seborrheic Dermatitis arises in more extensive and refractory patterns in up to 83% of HIV-seropositive and AIDS patients. It may initially present as a butterfly-like rash seen in Systemic Lupus Erythematosus (SLE) and is associated with a reduction in T-cell function, worsening as the CD4+ count decreases.
What factors contribute to the etiology and pathogenesis of Seborrheic Dermatitis (SD)?
The etiology of SD is multifactorial, involving several endogenous and exogenous factors, including the role of sebaceous glands, the immunologic status of patients, Malassezia as a normal skin flora, and seasonal fluctuations and sun exposure.
How does the immune response relate to Seborrheic Dermatitis (SD)?
In immunosuppressed patients, SD is more common. Studies show increased production of interleukins (IL-1, IL-4, IL-12, TNF, IFN-γ) in lesions, and inflammatory genes are expressed in uninvolved skin, suggesting predisposing factors for inflammation in SD patients.
What microbial effects are associated with Seborrheic Dermatitis (SD)?
Malassezia, a normal skin flora, is important in SD. Common lesions of SD are related to sebaceous glands where Malassezia colonizes, and antifungal medications have therapeutic effects against SD.
What lipid and host susceptibility factors are associated with Seborrheic Dermatitis (SD)?
Individual susceptibility to SD is linked to a disrupted epidermal barrier, allowing irritating metabolites to penetrate. Irritating free fatty acids (FFAs) can mediate dandruff-like flaking in susceptible individuals.
What are the associations between seborrheic dermatitis (SD) and HIV/AIDS, particularly regarding T-cell function and disease progression?
Seborrheic dermatitis (SD) arises in more extensive and refractory patterns in up to 83% of HIV-seropositive and AIDS patients, associated with a reduction in T-cell function and worsening as the CD4+ count decreases.
How does the immunologic status of patients influence the susceptibility to seborrheic dermatitis (SD)?
The immunologic status of patients significantly influences susceptibility to SD, being more commonly seen in individuals with underlying diseases such as AIDS and Parkinson’s disease.
What role does Malassezia play in the pathogenesis of seborrheic dermatitis (SD)?
Malassezia, a normal skin flora, is suggested to be important in the pathogenesis of SD, with common lesions related to sebaceous glands where Malassezia preferentially colonizes.
What are the potential microbial effects of Malassezia in patients with seborrheic dermatitis (SD)?
Malassezia can induce inflammation in SD patients by colonizing sebaceous glands, producing lipase and phospholipase, and disturbing protective skin barriers.
How do lipid and host susceptibility factors contribute to the development of seborrheic dermatitis (SD)?
Individual susceptibility to SD is associated with a disrupted epidermal barrier that allows irritating metabolites to penetrate, with irritating FFAs mediating dandruff-like flaking in susceptible individuals.
A patient with seborrheic dermatitis is found to have a high concentration of Malassezia furfur. How does this contribute to the disease?
Malassezia furfur disturbs protective skin barriers and induces inflammation, contributing to the pathogenesis of seborrheic dermatitis.
A patient with AIDS presents with extensive, refractory seborrheic dermatitis. What underlying immunological changes contribute to this presentation?
The reduction in T-cell function and decreased CD4+ count in AIDS patients contribute to the extensive and refractory nature of seborrheic dermatitis.
A 50-year-old female presents with thick, silvering scales on her scalp that are firmly adherent to both the scalp and hair tufts. What is the condition, and what are its common associations?
The condition is pityriasis amiantacea, commonly associated with psoriasis (35%) and eczematous conditions like seborrheic dermatitis (SD) and atopic dermatitis (AD) (34%).
A patient with seborrheic dermatitis has been prescribed ketoconazole shampoo. What is the rationale behind using this treatment?
Ketoconazole is an antifungal agent effective against Malassezia species, which are implicated in the pathogenesis of seborrheic dermatitis.
What role does epidermal hyperproliferation play in seborrheic dermatitis (SD)?
Epidermal hyperproliferation is implicated in SD, leading to increased epidermal turnover and resembling psoriasis both clinically and histologically.
How do neurotransmitter abnormalities affect the severity of seborrheic dermatitis in patients with Parkinson’s disease?
In Parkinson’s disease, the severity of SD does not correlate with sebum excretion rate; instead, sebum accumulation due to facial immobility may play a key role.
What factors can contribute to the severity of seborrheic dermatitis?
Factors contributing to the severity of SD include low humidity and cold temperatures, facial trauma, certain medications, zinc or biotin deficiency, and an indoor lifestyle with less sunlight exposure.
What are the diagnostic criteria for infantile seborrheic dermatitis (ISD)?
The classic diagnostic criteria for ISD include early onset (before 6 months of age), erythematous and scaling rash distributed in the scalp, diaper, or flexural areas, and relative absence of pruritus.
What histopathological features differentiate acute and chronic seborrheic dermatitis?
The histopathological features include:
Type of Dermatitis | Features |
|——————-|———-|
| Acute and Subacute SD | Mild psoriasiform hyperplasia, spongiotic dermatitis, scattered neutrophils, orthokeratosis with focal parakeratosis, superficial perivascular lymphohistiocytic infiltration |
| Chronic SD | More intense features with minimal spongiosis, markedly dilated superficial vessels, sometimes similar to psoriasis |
| HIV-associated SD | Very severe patterns |
What role does epidermal hyperproliferation play in seborrheic dermatitis (SD) and how does it relate to psoriasis?
Epidermal hyperproliferation in SD indicates a disorder of increased epidermal turnover, resembling psoriasis both clinically and histologically, linked to heightened activity of calmodulin.
How do neurotransmitter abnormalities influence the severity of seborrheic dermatitis in patients with Parkinson’s disease?
In Parkinson’s disease, the severity of SD does not correlate with sebum excretion rates; instead, facial immobility may lead to sebum accumulation, contributing to the condition.
What factors can exacerbate seborrheic dermatitis, particularly in relation to environmental and lifestyle conditions?
Factors that can exacerbate seborrheic dermatitis include low humidity and cold temperatures, facial trauma, PUVA therapy, certain medications, zinc or biotin deficiency, and an indoor lifestyle with less sunlight exposure.
What are the histopathological differences between classic seborrheic dermatitis and HIV-associated seborrheic dermatitis?
The histopathological differences include:
Feature | Classic Seborrheic Dermatitis | HIV-associated Seborrheic Dermatitis |
|———|——————————|————————————-|
What is PUVA therapy?
PUVA therapy is a treatment method that combines a drug called psoralen with ultraviolet A (UVA) light.
What medications may contribute to seborrheic dermatitis?
Certain medications, such as griseofulvin and lithium, may contribute to seborrheic dermatitis.
How do zinc deficiency and biotin deficiency relate to seborrheic dermatitis?
Zinc deficiency or biotin deficiency can lead to skin issues similar to seborrheic dermatitis.
What lifestyle factors can exacerbate seborrheic dermatitis?
An indoor lifestyle with less sunlight exposure and poor hygiene can exacerbate seborrheic dermatitis.
What are the histopathological differences between classic seborrheic dermatitis and HIV-associated seborrheic dermatitis?
Classic seborrheic dermatitis shows rare necrotic keratinocytes, prominent spongiosis, thin-walled vessels, and rare plasma cells. In contrast, HIV-associated seborrheic dermatitis shows many necrotic keratinocytes, sparse spongiosis, many thick-walled vessels, and increased plasma cells.
What are the classic diagnostic criteria for infantile seborrheic dermatitis (ISD)?
The classic diagnostic criteria for ISD include early onset (before 6 months of age), erythematous and scaling rash in the scalp, diaper, or flexural areas, and relative absence of pruritus.
What is the mechanism of action of azelaic acid in seborrheic dermatitis?
Azelaic acid acts as a cytostatic medication, targeting increased activity of calmodulin and epidermal hyperproliferation.
What environmental factors might exacerbate seborrheic dermatitis during winter?
Low humidity and cold temperatures during winter can exacerbate seborrheic dermatitis.
Why is it important for patients with seborrheic dermatitis to avoid scratching?
Scratching can lead to facial trauma, which exacerbates seborrheic dermatitis.
How does zinc deficiency contribute to seborrheic dermatitis?
Zinc deficiency can impair skin barrier function and immune response, leading to SD-like dermatitis.
What neurological factors might contribute to the severity of seborrheic dermatitis in patients with cerebrovascular infarcts?
Neurological factors such as facial immobility and neurotransmitter abnormalities can exacerbate seborrheic dermatitis.
What dermoscopy findings suggest seborrheic dermatitis?
Dermoscopy may reveal twisted loops and red dots, aiding in distinguishing it from conditions like scalp psoriasis.
What distinguishes infantile seborrheic dermatitis from other conditions?
The involvement of the diaper area alone is a characteristic sign of the psoriasiform type of ISD.
What are the distinctive features of scalp psoriasis?
Scalp psoriasis may involve frontal hair lines and present with purpuric lesions that desquamate and ulcerate on folds and mucosal areas.
What is the primary goal of treatment for seborrheic dermatitis in adolescents or adults?
The primary goal is to control symptoms rather than to cure the disease.
What are the first-line treatment options for managing seborrheic dermatitis?
First-line treatment options include topical corticosteroids, topical calcineurin inhibitors, topical antifungal drugs, and keratolytics.
What management strategies are recommended for refractory cases of seborrheic dermatitis?
Recommended strategies include low doses of systemic glucocorticoids, oral antifungals, oral isotretinoin, and NB UVB phototherapy.
What are the key differential diagnoses for seborrheic dermatitis on the scalp?
Key differential diagnoses include psoriasis, Langerhans cell histiocytosis, scabies, and intertrigo.
What is the recommended management for seborrheic blepharitis?
Management includes long-term eyelid hygiene with warm compresses, followed by topical antibiotics and corticosteroids.
What is the dosing regimen for oral itraconazole in seborrheic dermatitis?
Itraconazole is prescribed at 200 mg/day for the first 7 days of the month for several months.
What is the mechanism of action of coal tar in treating seborrheic dermatitis?
Coal tar reduces scaling and inflammation by slowing down epidermal turnover.
What is the therapeutic benefit of salicylic acid shampoo?
Salicylic acid acts as a keratolytic, helping to remove scales and reduce flaking.
What is the mechanism of action of ciclopirox shampoo?
Ciclopirox has antifungal properties, targeting Malassezia species involved in seborrheic dermatitis.
What is the therapeutic benefit of zinc pyrithione shampoo?
Zinc pyrithione has antifungal and antibacterial properties, reducing Malassezia colonization and inflammation.
What is the mechanism of action of isotretinoin in seborrheic dermatitis?
Isotretinoin reduces sebaceous gland activity and inflammation.
What is the mechanism of action of ketoconazole cream?
Ketoconazole cream targets Malassezia species by inhibiting fungal cell membrane synthesis.
What is a potential side effect of prolonged use of topical corticosteroids?
Prolonged use can lead to skin atrophy and telangiectasia.
What is the mechanism of action of fluconazole in seborrheic dermatitis?
Fluconazole inhibits fungal cell membrane synthesis, targeting Malassezia species.
What is a potential advantage of topical calcineurin inhibitors over corticosteroids?
Calcineurin inhibitors do not cause skin atrophy, making them suitable for long-term use.
What is a potential advantage of NB-UVB phototherapy?
NB-UVB phototherapy is non-invasive and has immunomodulatory and anti-inflammatory effects.
What is the mechanism of action of pramiconazole in seborrheic dermatitis?
Pramiconazole inhibits fungal cell membrane synthesis, targeting Malassezia species.
What is a potential side effect of selenium sulfide shampoo?
Selenium sulfide can cause skin irritation and dryness if overused.
Why are topical calcineurin inhibitors preferred in certain regions?
They are recommended for regions susceptible to telangiectasia and skin atrophy caused by corticosteroids.
What are the recommended management options for Infantile Seborrheic Dermatitis?
Options include using superabsorbent disposable diapers, cleaning with soap and alcohol-free compounds, applying topical antifungal treatments, and using mild-potency topical steroids.
How does Infantile Seborrheic Dermatitis differ from Atopic Dermatitis?
ISD is self-limited, primarily affects the vertex scalp, and presents with greasy scales, while atopic dermatitis is intensely pruritic and primarily affects the face.
What evidence supports the use of tea tree oil in seborrheic dermatitis?
Tea tree oil has antifungal properties against Malassezia furfur and improves severity, pruritus, and greasiness.
What is the nature of seborrheic dermatitis?
Self-limited, regresses spontaneously
Severity decreases with age.
What are the lesion characteristics of seborrheic dermatitis?
Adherent, yellow-brown, greasy scale
Intensely pruritic, erythematous papules with excoriation, vesicles, and serous exudate.
What evidence supports the use of tea tree oil for seborrheic dermatitis?
Tea tree oil has antifungal properties, particularly against Malassezia furfur, and has been shown to improve severity, pruritus, and greasiness in seborrheic dermatitis.
Why is 1% hydrocortisone preferred over higher-potency steroids for infants with seborrheic dermatitis?
Mild-potency steroids like 1% hydrocortisone are preferred to minimize the risk of side effects in infants.
Why should patients with seborrheic dermatitis avoid alcohol-based cleaning agents?
Alcohol-based agents can irritate the skin and exacerbate seborrheic dermatitis.
