Lichen sclerosus (LS) is an uncommon, chronic, inflammatory mucocutaneous disorder found predominantly in females with unknown etiology. It presents as a white sclerotic plaque commonly located on the anogenital area. Extragenital LS is less prevalent, and LS affecting the oral mucosa is extremely rare, with only 39 biopsy-confirmed cases reported in the literature. Due to its several mimicking conditions, histological examination is usually required for a definitive diagnosis, particularly in patients with oral LS. Current evidence-based treatment recommendations for oral LS are unavailable; however, most cases tend to improve after treatment with topical or intralesional corticosteroids. We report a case of a 58-year-old female referred from the otolaryngology department for evaluating an asymptomatic whitish sclerotic plaque on the lower lip mucosa that had existed for 1 year. Following a punch biopsy, the patient was diagnosed with LS of labial mucosa. The condition improved after 2 months of treatment with topical and intralesional corticosteroids. The present case report raises awareness in recognizing oral LS and contributes to knowledge of this rare disorder.

Immune checkpoint inhibitors such as anti-PD-1 receptor antibodies have been shown to be effective in patients with advanced gastric cancer. However, there is a growing concern about immune-related adverse events. A case of a patient with gastric adenocarcinoma who developed toxic epidermal necrolysis (TEN) induced by sintilimab and subsequently developed lichenoid dermatitis is reported. TEN was diagnosed according to a history of sintilimab use, clinical symptoms and physical examination. During hospitalization, the patient developed recurrent fever caused by bacteremia and recovered from TEN after anti-infection and anti-inflammatory treatments. However, when TEN was controlled, the patient developed the lesional manifestations of lichenoid dermatitis. To date, no cases of lichenoid dermatitis after TEN have been reported following the use of PD-1 inhibitors.
PD-1 inhibitors are drugs that help fight stomach cancer but can sometimes cause skin problems. Most skin problems are minor and do not have a serious impact on the patient\'s health. However, life-threatening skin problems such as toxic epidermal necrolysis (TEN) can sometimes happen. This case report describes a patient with stomach cancer who had lichenoid dermatitis (another skin problem) after TEN, following the treatment of his cancer with PD-1 inhibitors. To the best of our knowledge, it is very rare to experience both skin problems after treating cancer with PD-1 inhibitors. This rare phenomenon is reported to bring more attention to it. More research is needed to determine how to treat this problem better.

Infliximab is a tumor necrosis factor-alpha inhibitor used to treat a range of inflammatory diseases. Most reports of cutaneous eruptions from tumor necrosis factor-alpha inhibitors have described the paradoxical development of psoriasis or psoriasiform drug reaction. In our report, we present a 31-year-old female with inflammatory bowel disease who developed an unusual lichenoid drug reaction to infliximab involving the hair follicles, resulting in progressive global alopecia. Clinical features and histopathological findings were consistent with drug-induced lichen planopilaris with eosinophils and lichenoid dermatitis.

BACKGROUND: Lichenoid granulomatous dermatitis (LGD) is an uncommon reaction pattern for which clinical correlates can be difficult to establish. LGD combines vacuolar degeneration with variable types of granulomas.
OBJECTIVE: To determine clinical correlates of LGD.
METHODS: The laboratory information systems at the University of Florida, the Medical College of Wisconsin, and Inform Diagnostics Research Institute were queried to identify 56 cases of LGD. Cases were reviewed for information regarding eosinophils, plasma cells, deep perivascular infiltrates, granuloma subtype, parakeratosis, epidermal atrophy, psoriasiform epidermal changes, pseudoepitheliomatous hyperplasia, periadnexal inflammation, vasculitis, and red blood cell extravasation.
RESULTS: The most common clinical correlates were drug eruption (39.3%, n = 22) and lichenoid keratosis (19.6%, n = 11). Tattoo reaction, postherpetic dermatitis, and scabies or postscabietic dermatitis each accounted for 7.1% (n = 4) of cases. Pigmented purpuric dermatosis and lichen striatus each accounted for 5.4% (n = 3) of cases. Dermal eosinophils (P = .005) and psoriasiform epidermal changes (P = .055) were associated with drug hypersensitivity. Perineural (P = .049) and perifollicular (P = .003) inflammation were associated with tattoo reaction and postherpetic dermatitis. Red blood cell extravasation was helpful in cases of pigmented purpuric dermatosis (P = .049).
CONCLUSIONS: This study is limited by its retrospective nature and statistical power.
CONCLUSIONS: Dermal eosinophilia, psoriasiform epidermal changes, periadnexal inflammation, and red blood cell extravasation might aid in the clinical diagnosis of patients with LGD.

BACKGROUND: Annular lichenoid dermatitis of youth (ALDY) is a rare form of dermatitis mainly affecting children and young people. All cases reported show a consistent clinical and histological picture. This is the first case described in the French literature.
METHODS: A 5-year-old girl presented an annular isolated patch of the lower abdomen with an erythematosquamous border and central hypopigmentation for one year. Topical corticosteroids and pimecrolimus proved effective but relapse occurred after treatment withdrawal.
CONCLUSIONS: Over sixty cases of ALDY are described in the English-language medical literature. The main differential diagnosis is childhood mycosis fungoides, particularly the hypopigmented variant. Biopsy is necessary for diagnosis since it can reveal typical histological features. Histopathology in all cases shows lichenoid reaction with CD4+ and CD8+ polyclonal lymphocytes. It is limited to the tips of rete ridges and associated with apoptosis of keratinocytes resulting in quadrangular-shaped rete ridges. Our case does not demonstrate either epidermotropism or atypical lymphocytes.
CONCLUSIONS: Annular lichenoid dermatitis of youth (ALDY) is a poorly known distinctive entity within the lichenoid dermatitis family. Clinical-histological correlation is essential to diagnosis. The etiology is still unknown and the course is mostly chronic.