Polymorphic eruption of pregnancy

Histopathological features of pemphigoid gestationis and polymorphic eruption of pregnancy: A blinded retrospective comparative study of 31 cases

BACKGROUND

Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) are pregnancy-related dermatoses. Definitive diagnosis often relies upon histopathology and direct immunofluorescence (DIF). PG is associated with fetal and neonatal risks, while PEP confers minimal risk.

OBJECTIVE

We aimed to compare histopathologic features to determine key differentiators.

METHODS

A retrospective cohort study of PG and PEP cases, with accompanying DIF, conducted from 1995 to 2020. Skin biopsies were examined independently in a blinded fashion by two dermatopathologists for a list of histopathological features.

RESULTS

Twenty-one cases of PG and 10 cases of PEP were identified. PG had significantly denser eosinophils than PEP (mean 155 vs. 48 cells/5 hpf; p < 0.018). PG was also noted to have eosinophilic spongiosis and eosinophils at the dermal-epidermal junction more frequently compared to PEP (80% PG vs. 10% PEP; p < 0.001). A mean cutoff value of 86 eosinophils and a mean optimal sensitivity and specificity of 81% and 83%, respectively, for eosinophils density's diagnostic power of PEP versus PG were achieved. Subepithelial separation was exclusively seen in PG (40% vs. 0%; p < 0.007).

CONCLUSION

Eosinophilic spongiosis, eosinophilic epitheliotropism, and dense superficial dermal eosinophils were diagnostic of PG. Given overlapping clinicopathologic features, however, DIF results with clinicopathologic correlation, remain the gold standard.

Recognizing, Diagnosing, and Managing Pregnancy Dermatoses

Pregnancy dermatoses are inflammatory skin disorders that occur during pregnancy or immediately postpartum. This heterogenous group of disorders includes pemphigoid gestationis, polymorphic eruption of pregnancy, intrahepatic cholestasis of pregnancy, atopic eruption of pregnancy, and pustular psoriasis of pregnancy. In this article, we provide a comprehensive literature review of each condition focusing on nomenclature, epidemiology, pathogenesis, clinical presentation, diagnosis, differential diagnosis, maternal risk, fetal risk, and treatment. We aim to increase awareness and help clinicians recognize, diagnose, and manage these unique conditions.

Annular urticarial lesions

Annular urticarial configurations are often associated with acute and chronic urticaria. Such lesions may be short-lived, migratory, transient, pruritic, and resolving with no residual evidence, making the diagnosis of urticaria an obvious one. Annular urticarial lesions can be the presenting signs of various cutaneous and systemic diseases. The differentiation of urticarial lesions may be made by considering the duration of an individual lesion longer than 24 hours, with burning and pain sensation in the lesions or lack of pruritus; skin marks such as postinflammatory pigmentation or purpura after resolution of the lesions; associated scaling or vehiculation in the lesions; systemic symptoms such as arthralgia, fever or fatigue; and several abnormal laboratory findings. The main differential diagnoses of annular urticarial lesions include urticarial vasculitis, autoinflammatory syndromes, hypersensitivity reactions, and connective tissue diseases.

Chronic Urticaria and Recurrent Angioedema: Clues to the Mimics

Urticaria and angioedema are experienced by up to 1 in 5 people, usually the result of common allergen or medication triggers and infections. Similarly, the majority of recurrent angioedema has an exogenous trigger, for example, angiotensin converting enzyme inhibitors, or is hereditary (type 1 and 2 hereditary angioedema); chronic spontaneous urticaria are most often autoimmune or autoallergic in routine clinical practice. There are, however, several skin and systemic conditions that can imitate the clinical appearance of either angioedema or urticaria, whereas there are several uncommon conditions that have chronic urticaria and/or recurrent angioedema as part of their disease manifestations. Correct diagnosis is paramount to ensuring subsequent tailored therapy for many of these conditions, and in many instances, diagnostic delay can be several years with morbid consequence. In this grand rounds article, we present 2 illustrative clinical cases as the backdrop to discussing a practical diagnostic approach for clinicians to recognize copycat phenotypes and "red flags" that should prompt further investigation of several uncommon mimics. We highlight key diagnostic features, epidemiology, and management for mimics where treatment is distinct from the common phenotypes of recurrent angioedema and chronic urticarias.

Specific dermatoses of pregnancy other than pemphigoid gestationis

Specific dermatoses of pregnancy are skin disorders that occur specifically during or immediately after pregnancy and cannot be found in non-pregnant patients. According to the current consensus, they include atopic eruption of pregnancy (AEP), polymorphic eruption of pregnancy (PEP), pemphigoid gestationis (PG), and intrahepatic cholestasis of pregnancy (ICP). The diagnosis of specific dermatoses of pregnancy can be challenging due to their variation in clinical presentation; moreover, the tests currently available do not always provide the clue for the diagnosis. However, some distinctive features may be helpful to differentiate between such entities. Accordingly, the knowledge of specific dermatoses of pregnancy and of their management is critical, since their early recognition may allow to provide care for the mother and prevent potential increased fetal risk. In fact, while AEP and PEP do not affect maternal and fetal prognosis, PG and, mainly, ICP are associated to maternal complications as well as the risk of fetal loss. In this paper, the epidemiology, pathogenesis, clinical features as well as management of AEP and PEP are reviewed in detail, while PG is described in another article of this issue. Moreover, the main features of ICP, which cannot be considered a primarily skin disease but may be managed first by dermatologists, are reported.