103: Neonatal Dermatology Flashcards
(139 cards)
At 6 weeks of gestational age, the epidermis develops a basal cell layer and a superficial periderm layer. What is the significance of the periderm?
The periderm does not contribute to the formation of stratified squamous epithelium and is shed during the end of the 2nd trimester, indicating its temporary role in skin development.
How does the epidermal barrier function differ between term and preterm neonates?
In term neonates, the epidermal barrier function is fully developed by 2-4 weeks of life, while in preterm neonates, particularly those born before 34 weeks, the barrier function is markedly decreased and may take longer to mature.
What are the implications of increased transepidermal water loss (TEWL) in preterm neonates?
Increased TEWL in preterm and low birthweight neonates reflects epidermal barrier immaturity and is associated with a higher risk of infection and sepsis due to skin fragility and potential entry points for pathogens.
What changes occur in the thickness of the stratum corneum during the first three months of life?
During the first three months of life, the thickness of the stratum corneum decreases, while epidermal thickness increases, leading to the formation of dermal papillae and epidermal ridges.
What role does vernix caseosa play in neonatal skin development?
Vernix caseosa is produced around 36 weeks of gestation and is crucial for epidermal maturation and the formation of the stratum corneum. It has antimicrobial, antioxidant, and barrier functions, contributing to skin protection.
What is the neonatal period defined as?
The first 30 days of life.
At what gestational age does the epidermis begin to develop?
6 weeks of gestational age.
When does the functional maturation of the stratum corneum begin in preterm infants?
Around 24 weeks of gestation.
What happens to the thickness of the stratum corneum in the first 3 months of life?
It decreases, while epidermal thickness increases.
How does thermal regulation function in premature infants?
It is dysfunctional due to a thin subcutaneous fat layer and poor autonomic control.
What is the role of emollient therapy in premature infants?
It improves skin integrity but may increase the risk of systemic candidiasis.
What is the typical skin pH in term and preterm neonates compared to older infants?
It is more alkaline in term and preterm neonates.
What are the key developmental milestones of the epidermis during the first 6 weeks of gestation in neonates?
- 6 weeks: Epidermis begins to develop as a basal cell layer and a superficial periderm layer.
- 8 weeks: Stratification of fetal epidermis and DEJ evident.
- 11-15 weeks: Terminal differentiation first in skin appendages, then in interfollicular epidermis.
- 15 weeks: Collagen fiber formation and organization of papillary and reticular dermis.
- 22-24 weeks: Epidermis consists of 4-5 cell layers, elastic fibers noted.
How does the epidermal barrier function differ between term and preterm neonates, and what are the clinical implications?
- Term Neonates:
- Full barrier function achieved by 2-4 weeks of life.
- TEWL is equivalent to adults after drying of the skin.
- Preterm Neonates:
- Markedly decreased epidermal barrier function, particularly in those born before 34 weeks.
- Functional maturation of the stratum corneum begins around 24 weeks, may take longer than 4 weeks in very preterm infants.
- Clinical Implications:
- Increased risk for infection and sepsis due to fragile skin.
- Higher TEWL rates lead to greater fluid loss and potential for dehydration.
What are the risks associated with thermal regulation in premature infants, and how should they be managed?
- Risks:
- Dysfunctional thermal regulation due to thin subcutaneous fat layer.
- Decreased ability to sweat and poor autonomic control of cutaneous blood vessels.
- Large surface-area-to-body-mass ratio increases heat loss.
- Management:
- Place premature infants in a temperature and humidity controlled isolette.
- Monitor temperature and fluid regulation until stabilized.
- Consider the use of radiant warmers and phototherapy cautiously, as they can increase TEWL.
What is the significance of vernix caseosa in neonates, and how does its production correlate with skin development?
- Vernix Caseosa:
- A lipid-rich substance produced by sebaceous glands, beginning around 36 weeks of gestation.
- Composed of water-containing corneocytes in a lipid matrix, providing antimicrobial and antioxidant properties.
- Significance:
- Plays a crucial role in the maturation of the epidermal barrier and formation of the stratum corneum.
- Protects the skin from environmental factors and aids in skin hydration.
What are the recommendations for routine skin care in neonates?
- Bathing in water 2 to 3 times per week for no more than 5 to 10 minutes using a gentle soap-free liquid skin cleanser instead of a washcloth.
- Application of an emollient after bathing.
- An appropriate skin-care regimen minimizes overbathing, maintains the epidermal barrier, and reduces exposure to irritants.
- Less is best to avoid irritation and allergic contact dermatitis.
What are some considerations regarding the use of topical substances in neonates?
Neonates have an increased risk for systemic toxicity from topically applied substances due to:
- Greater surface-area-to-body-mass ratio compared to adults.
- Preterm neonates have an even greater ratio, increasing the risk of toxicity.
- Differences in metabolism, excretion, and protein binding of substances compared to adults, which can magnify adverse effects, especially in preterm neonates.
What are the characteristics and resolution timeline of caput succedaneum?
Caput succedaneum is characterized by:
- Subcutaneous edema over the presenting part of the head due to pressure against the cervix.
- Common occurrence in newborns, soft to palpation with ill-defined borders.
- Petechiae and ecchymosis may also be noted.
Resolution: Typically resolves spontaneously over 7 to 10 days.
What is the typical presentation and resolution of milia in newborns?
Milia are:
- 2-mm papules that are benign, superficial epidermal inclusion cysts, usually few in number.
- Most commonly found on the face in newborns.
- Generally resolve spontaneously within a few weeks of life.
- Persistent or numerous milia may be associated with rare genetic disorders: oral-facial-digital syndrome, Bazex-Dupré- Christol syndrome, and
Basan syndrome
What is the difference between caput succedaneum and cephalohematoma?
Caput succedaneum is soft and ill-defined, while cephalohematoma is a firm collection of blood that respects suture lines and may be associated with skull fractures.
What is sebaceous gland hyperplasia?
A condition where at least 50% of normal newborns have minute yellow macules or papules at the opening of pilosebaceous follicles, resolving spontaneously by 4 to 6 months of age.
What are the distinguishing features of caput succedaneum and cephalohematoma in neonates?
Caput Succedaneum
- Subcutaneous edema over the presenting part of the head
- Soft to palpation with ill-defined borders
- Petechiae and ecchymosis may be noted
- Resolves spontaneously over 7 to 10 days
Cephalohematoma
- Collection of blood between the skull and periosteum, respects suture lines
- Firm to palpation, usually unilateral
- Associated with birth trauma or vacuum extraction
- Usually resolves without sequelae over several weeks, but calcification may occur
What is erythema toxicum neonatorum and how does it typically present in newborns?
- Erythema Toxicum Neonatorum: An idiopathic skin condition seen in up to 75% of term newborns.
- Presentation: Characterized by blotchy erythematous patches 1-3 cm in diameter with a 1-4 mm central vesicle or pustule.
- Onset: Eruption usually begins at 24 to 48 hours of age, but can be delayed up to 10 days.
- Location: Lesions can be located anywhere but tend to spare the palms and soles.
- Resolution: Clears spontaneously by 2 to 3 weeks of age without residua.