Pregnancy dermatoses Melissa Flashcards
Pemphigoid gestationis -when
Onset from 4/52 gestation to 1/52 post partum
- Commonest 21-28/52
- Subsequent pregnancy onset usually earlier
- May become quiescent later in pregnancy then flare post-partum
- Usually lasts weeks months after birth, Occasionally lasts years
Pemphigoid gestationis: May be seen with…
May also be seen with hydatiform moles and choriocarcinoma
Fathers more often HLA-DR2
Pemphigoid gestationis: antigen
BP 180 (BPAG2; collagen XVII) > 230 Predominantly IgG1
Pemphigoid gestationis
PROGNOSIS
Often flares at delivery
3-10% Infant can have blistering in the 1st 2/52 emollients only
May be weeks, months to years before resolution
Exacerbation may be seen with menstruation
OCP flare contraindicated whilst disease active
Likely to recur in subsequent pregnancy
More or less severe 10% of subsequent pregnancies are normal
Pemphigoid gestationis- exam and spares what
- Urticated papules, plaques and target lesions
- Blisters & vesicles arise within
- Eruption often begins around the umbilicus
- Spreads to abdomen and thighs
- Extremities, palms and soles can be affected
- Spares mucosa, face, palms, soles
- Can spread to neonate
Pemphigoid gestationis associations and risks
Associations Autoimmune diseases such as - Graves' - Vitiligo - Alopecia areata Association with premature delivery and risk of low birth weight, neonatal pemphoid gestationis
Pemphigoid gestationis
TREATMENT
General
Education about current and subsequent pregnancies
Consider admission
Topical
Mild cases may get by with potent topical steroids alone
Systemic
Prednisolone (40mg/d) 0.5mg/kg – taper as soon as blister formation suppressed.
Use once blistering occurs
May need to increase post-partum for flares
Does pass into milk
Antihistamines - Will pass into breast milk drowsiness
2nd / 3rd Line Rx
IVIG, Plasmapheresis, AZA (as an adjunct with steroids)
Pemphigoid gestationis - dapsone could be used
Dapsone contraindicated
Not effective and causes haemolytic disease of the newborn
Pemphigoid gestationis - histo
Histopathology
Early : Epidermal and papillary dermal oedema
Occasional foci of eosinophilic spongiosis
Later: subepidermal blisters filled with eo’s
C3 linear deposition along BMZ
IgG1 autoantibodies directed against a transmembrane hemidesmosomal protein (BP180; collagen XVII)
DIF:IgG (30%) + C3 (100%) in linear pattern
Also seen in BP, HG, EBA and bullous SLE
IgG1 > IgG4 in PG vice versa in BP 1 > 4
May see only linear C3 in BP & HG
Differentiating between these two is impossible on DIF or histo
Salt split skin IgG epidermal fragment
IIF +ve in 10%
HG factor amplified IIF procedure
Amplified and detected by the complement binding properties of the antibody 50% +ve
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy: how common
1:130-1:300
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy . who and when
during later portion of 3rd trimester or immediately post partum.
Primiparous women usually. Higher risk: multiples, male fetus, C section.
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy - recurs?
Does not recur unless multiple gestation, no maternal or fetal risks Unusual to recur with OCP
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Prengnancy
clinical features
Urticarial papules and plaques +/- vesicles usually in striae. Usually periumbilical sparing. Spares face, palms, soles
Duration – 6/52
Spontaneous remission within a few days of delivery.
Development of polymorphous features (vesicles, erythema, target and eczematous lesions) with disease progression
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy - aeitology
Aeitology:
abdominal skin may lead to damage of connective tissue and elicitation of allergic type reaction. Cross reactivity to collagen
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy DDx
DDx: urticarial pemphioid gestationis, Pemphigoid gestationis, atopic eruption of pregnancy. Also drug eruption, viral exanthema, pityriasis rosea, eczematous dermatitis, scabies.
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy
Tx
Topical CS, pred if bad
Reassurance
Polymorphic eruption of pregnancy=Pruritic Urticarial Papules and Plaques of Pregnancy
Histo
- Non specific
- Spongiosis , acanthosis with hyperkeratosis and parakeratosis
- Sometimes exocytosis of eosinophilis
Which drugs to use in pregnancy
pred
antihistamines
topicals
Antihistamines
o Chlorpheniramine : 1st trimester
o 2nd/3rd: loratadine
Systemic
o Pred: largely inactivated in placenta mother:fetus 10:1
o 1st trimester weeks 8-11: possible increased risk of cleft lip/palate esp if high doses are prescribed and for >10 days; longer duration of therapy ok if doses are
physiological changes in pregnancy
- Hyperpigmentation o Melasma 70%, areola/linear nigra (90%) - Hair o Hirsutism o Telogen effluvium – may last up to 15 months o Post partum androgenic alopecia - striae o up to 90% - vascular o spider angiomas, pyogenic granulomas
Pustular psoriasis of pregnancy = impetigo herpetiformis
May be concerned as a type of pustular psoriasis BUT often has absence of +ve family hx, abrupt resolution of sx at delivery, a tendancy to recur at subsequent pregnancies. Factors known to trigger pustular psoriasis eg infection, drugs, rebound from steroids are often absent
Pustular psoriasis of pregnancy = impetigo herpetiformis
Usual onset 3rd trimester
Pustular psoriasis of pregnancy = impetigo herpetiformis Maternal and foetal risk
Foetal risk: placental insufficiency may lead to stillbirth or neonatal death
Maternal risk: sepsis or hypocalcaemia (rare)
Pustular psoriasis of pregnancy = impetigo herpetiformis Ix
Investigations FBC: leucocytosis, neutrophilia, anaemia ESR: elevated Albumin: low Ca, Phosphate, Vit D: may be low Culture: negative Swab: negative
Pustular psoriasis of pregnancy = impetigo herpetiformis features
Erythematous patches with subcorneal pustules at their margins.
Begins in flexures, generalises demonstrate centrifugal spread.
Often associated constitutional symptoms eg fever, chills, malaise, diarrhoea, nausea & arthralgias. Tetany, delirium and convulsions occur if hypocalcaemia is severe.
Pustular psoriasis of pregnancy = impetigo herpetiformis features
Tx
Resolution post delivery
Monitor fluids and electrolytes, cardiac & renal function
Fetal monitoring for decrease in HR (sign of hypoxaemia)
Topical treatments: wet dressings and topicals
Systemic CS
Cyclosporin 5-10mg/kg
nbUVB + steroids
Infliximab
Autoimmune progesterone dermatitis
- can appear during pregnanc or post partum
- cyclic flares of dermatitis which correspond to luteal phase
- tx involves inhibiting ovulation via estrogen containing preps
Atopic eruption of pregnancy
In pregnancy there is a switch to Th2 cytokine production (IL4 and IL10) less (IL12 – TH1) which worsens imbalance in atopic patients
Atopic eruption of pregnancy
where and who already has eczema and when
Eczematous or papular individuals with a person/familial atopic background and/or eleveated serum IgE.
75% before 3rd trimester
20% exacerbation of pre existing atopic dermatitis
2/3 lesions in atopic sites
1/3 papular eruption on trunk and extremities: prurigo or small erythematous papules, xerosis
20% flare of existing eczema
80% no hx of atopic eruption or after a long remission.
Intrahepatic cholestasis of pregnancy
TX
Treatment
Close foetal monitoring, may require early induction of labour
Reduce bile acid levels
Ursodeoxycholic acid : safe, only SE is mild diarrhoea 15mg/kg daily or 1g daily until delivery. Reduces maternal sx and fetal risk.
Enhances bile acid excretion.
Cholestyramine: May help 70% in mild-mod. Can take several days for effect. But may precipitate Vit K & a coagulopathy.
Bland emollients, antihistamines + UVB
Monitor coags
Remits at 2-4 weeks post delivery. May recur with OCP
Intrahepatic cholestasis of pregnancy
Presentation
Intense itching, worse at night
Starts palms and soles, then generalised
Jaundice only 10%-20% of patients
Pruritis persists until delivery
Protacted course is unusual – would need to look for other liver disease esp primary biliary cirrhosis
Fatigue, nausea, vomiting or anorexia
Intrahepatic cholestasis of pregnancy
pathogenesis
Reduced excretion of bile acids
Crossing placenta can lead to acute fetal anoxia due to abnormal uterine contractility and vasoconstriction of chorionic veins as well as impaired fetal cardiomyocyte function
One predisposing factor is mutations in genes that encode bile transporter proteins. When transporters capacity to secrete substrates is exceeded eg in setting of high levels of sex hormones in pregnancy, signs and symptoms of cholestasis can develop.
When and where
cholestatic eruption of pregnancy
Onset 3rd trimester (highest placental hormone levels)
10% 1st, 25% 2nd trimester
Recurs in 45-70% of subsequent pregnancies. Higher in multiple pregnancies. Can recur with OCP
Most common in south America, positive family hx in up to 50% - may be related to higher hormone levels
Higher risk hep C, selenium deficiency, increased intestinal permeability
Intrahepatic cholestasis of pregnancy
Diagnosis serum bile acid >11micromol/L (normal in non pregnant 0-6) – often >40
During pregnancy ALP usually increase due to placenta anyway and GGT levels are lower than in non pregnancy state.
Transaminases are usually elevated but may be normal in 30%
Hepatic USS is normal but may reveal gallstones in jaundiced patients
Intrahepatic cholestasis of pregnancy
Risk to mum: steatorrhea, vit K deficiency (increased risk of post partum haemorrhage), later risk of cholelithiasis or gallbladder disease
Highest risk to fetus: Increased risk of prematurity 20-60%, intrapartum fetal distress 20-30% and stillbirths 1-2% (increased placental anoxia, meconium stained amniotic fluid)
