Skin Flashcards
What are some physiological skin changes in pregnancy? (7)
- Increased pigmentation
- Melasma: light brown facial pigmentation, develops in approx 70% women, often in second half of pregnancy
- Spider naevi: face, upper trunk, arms
- Palmar erythema: present in up to 70% women by the third trimester
- Hypertrichosis and hirsutism: in response to high oestrogen and progesterone hair cycle stays in anogen phase promoting growth; 3-6 months postpartum changes to telogen phase and hair starts to fall out
- Striae gravidarum
- Pruritis (without rash or cholestasis)
What is a possible complication of psoriasis in pregnancy?
Impetigo herpetiformis (a rare, severe form of pustular psoriasis)
Urticated erythema, beginning in the flexures and particularly the groins, is associated with sterile pustules, which may become widespread and affect mucosa.
Condition associated with severe systemic upset - fever, neutrophilia, hypocalcaemia.
Rx: systemic corticosteroids, regular fetal surveillance
Obstetric implications:
- Increased risk of LBW
- Often recurs in subsequent pregnancies
NB. Most psoriasis improves in pregnancy
Of women with eczema, what % will suffer an exacerbation in pregnancy?
20%
What are the management options for Psoriasis in pregnancy?
1st - Emollients, topical corticosteroids, topical calcipotrial (a vit D analogue)
2nd - Narrowband UVB or broadband UVB
3rd - Ciclosporin and anti-TNF alpha biologics
NOT MTX: antimetabolite, teratogenic
Also contraindicated in pregnancy: hydroxyurea, acitretin
What is erythema nodosum?
Inflammation of the subcutaneous fat
Typically presenting as tender erythematous nodules over the anterior lower legs
May occur in pregnancy without any known cause
TB and Sarcoidosis should be excluded with a CXR
The woman should be asked about symptoms of streptococcal infection and IBD, as well as recent meds (esp. sulfonamides)
What is erythema multiforme?
Acute self-limiting condition predominantly affecting the peripheries
Symmetrical eruption
Erythematous Papules that evolve into concentric rings of varying colour with central pallor
May complicate pregnancy without obvious cause
Common causes: drugs, viral infections (particularly HSV)
What is the most common pregnancy-specific dermatosis?
PEP / PUPPP
Polymorphic eruption of pregnancy
Incidence 1:200, i.e. 0.5%
When does PEP normally present?
Third trimester
Mean gestational age at onset is 34/40
Resolves postpartum
What is the distribution of the rash in PEP?
Abdomen (with umbilical sparing), along the striae
Spreading to the thighs, buttocks, under the breasts and upper arms
How would you describe the rash seen in PEP?
Pruritic
Urticaria Papules and plaques,
Erythema
And rarely, vesicles or target lesions
What is the pathogenesis of pemphigoid gestationis?
Autoimmune (possibly related to exposure to fetal antigens)
Binding of circulating complement-fixing IgG antibodies to a protein (bullous pemphigoid antigen 2) in the hemidesmosomes of the basement membrane zone of the skin, triggers an immune response leading to the formation of sub-epidermal vesicles.
Associated with other autoimmune conditions e.g. Grave’s disease, vitiligo, T1DM, RA
How is pemphigoid gestationis diagnosed?
1) Skin biopsy and direct immunofluoresence
- shows complement (C3) deposition at the basement membrane zone.
- (negative in PEP)
2) Serum indirect immuonfloresecnece show antibodies in blood serum (30-100% cases)
What are the fetal risks in pemphigoid gestationis?
LBW
PTB
Suggestion of but less evidence for stillbirth
The neonate may be affected with a similar bullous eruption
This occurs in 10% cases and is mild and transient
What is the treatment for Pemphigoid gestationis?
- Topical potent or ultrapotent corticosteroids (e.g. 0.05% clobetasol propionate)
- MOST require Systemic steroids (e.g.g 40mg prednisolone od)
- Topical or systemic ciclsporin or tacrolimuis
- Sedating antihistamine
How would you describe the rash seen in Pemphigoid gestationis?
Intensely pruritis
Urticated erythematous papules and plaques
Target lesions
Annular wheals
After delay of approx 2/52: vesicles, large tense bullae form