Histopathologic Distinguishing Features Between Lupus and Lichenoid Keratosis on the Face

The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

Drug-induced cutaneous lupus erythematosus after immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy: a case series

We describe six patients with cutaneous lupus erythematosus (cLE) during immunoglobulin G (IgG) treatment. Five patients were diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) and one patient with possible CIDP. Five patients received intravenous immunoglobulin (IVIg) and one patient received subcutaneous immunoglobulin (SCIg). Skin lesions were systematically assessed by a dermatologist including skin biopsies. Patients showed disseminated erythematous plaques on several parts of the body with pre-dominance of the chest and face. Skin biopsies showed perivascular and perifollicular vacuolar inflammation, consistent with the diagnosis of cLE. There were no signs of systemic lupus erythematosus. Anti-SSA (Ro60) antibodies were found in two patients and anti-Ro52 antibodies were detectable in one patient. Symptoms improved in three patients after switching to another brand of IVIg and after use of topical corticosteroids. However, these measures did not lead to a complete resolution of the skin lesions. To achieve complete remission, IgG treatment was ceased in four patients. This led to remission of the skin lesions in two patients and to marked improvement in the other two patients. IVIg had to be restarted in two patients because of a relapse of CIDP which led to worsening of the skin lesions. In one patient with clear IVIg dependency, treatment was continued with addition of topical steroids. In the patient using SCIg, cLE was photosensitive and showed spontaneous remission. The relation of cLE with IgG treatment suggests an immunoglobulin-induced cLE. Only one report previously described the occurrence of IVIg induced cLE in a patient with common variable immunodeficiency.

Using Stratum Corneum Thickness and Configuration to Distinguish Lichenoid Dermatoses

BACKGROUND

Clues in the stratum corneum (SC) can aide in histopathologic diagnosis of many conditions.

OBJECTIVE

To determine if SC configuration and thickness could help differentiate the lichenoid dermatoses.

METHODS

A retrospective study was performed. A total of 305 cases (55 lichenoid keratosis, 51 lichen planus, 7 hypertrophic lichen planus, 40 lichenoid drug eruption, 19 lichenoid graft-vs.-host disease, 14 hypertrophic lupus, 46 lichenoid actinic keratosis, 73 lentigo maligna) fulfilled the selection criteria. Cases were digitally scanned using the 40× (0.23 μm/pixel) mode of a Hamamatsu NanoZoomer 2.0-HT Slide Scanner (Hamamatsu Photonics, Hamamatsu City, Japan), allowing for the creation of virtual (digital) slides. SC thicknesses and configuration were assessed for each case.

RESULTS

Mixed SC patterns were common in cases of lichenoid keratoses. Compact parakeratosis was the most common pattern in lichenoid drug eruption. Tiered parakeratosis was the most predominant pattern in cases of lichenoid graft versus host disease and lichenoid actinic keratosis. Hypertrophic lupus had the highest average SC thickness.

LIMITATIONS

The sample size for cases of hypertrophic lupus and hypertrophic lichen planus was low.

CONCLUSIONS

SC thickness and configuration can be utilized to help differentiate the lichenoid dermatoses.