Pityriasis Lichenoides et Varioliformis Acuta (PLEVA): Description and Histopathological Characteristics

Pityriasis lichenoides et varioliformis acuta (PLEVA) manifests through papules hemorrhagic which, upon resolution, leave pock-like scars. This condition is cataloged as a dermatosis acute and self-limiting. It is essential to mention that this condition is also recognized under the name Mucha Habermann disease.

Histological Analysis of PLEVA: Key Findings

The histopathological study of PLEVA reveals a infiltrate lymphocytic well-demarcated and moderately dense lymphocytic infiltrate affecting the plexus vascular superficial plexus. This infiltrate extends in a wedge-shaped pattern, encompassing the lower portion of the dermis (see Figure 1). In the superficial dermis, a dense lichenoid pattern infiltrate and notable lichenoid and a notable Inflammatory skin diseases examined through RCM can generally be classified into four main categories, allowing for more precise real-time diagnosis. of lymphocytes toward the epidermis. The stratum corneum superimposed stratum shows parakeratosis which can be confluent and contains accumulations of neutrophils (Figure 2).

Additionally, the epidermis exhibits marked hydropic changes and foci of necrosis of the keratinocyte. In this setting, scattered erythrocytes extravasated erythrocytes are also observed (Figure 3).

Figure 1

Figure 2

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Figure 5

Special Stains and Syndromes Associated with Sebaceoma

Images provided by Dr. Duncan Lamont, Waikato Hospital

Special Investigations and Immunohistochemical Markers in PLEVA

Generally, complementary studies are not required for the diagnosis of PLEVA. However, when immunoperoxidase studies are performed, they have revealed that the dominant lymphocytic infiltrate is composed of cytotoxic T Cells or cytotoxic properties. Typically, orb-weaving spiders produce neurotoxic venom, while other species, such as the violin spider or the yellow sac spider, secrete cytotoxic venom. CD8+ (see cytotoxic).

The diagnosis of pityriasis lichenoides et varioliformis acuta is primarily supported by clinical characteristics and typical histopathological findings. Understanding the cellular composition of the dermal infiltrate is crucial for differentiating this entity from other inflammatory dermatoses.