A 42-year-old woman with a past medical history of alcohol use disorder, decompensated alcoholic cirrhosis, systemic lupus erythematosus (SLE), rheumatoid arthritis, and celiac disease presented to the emergency department (ED) for a four-day history of painful rash with worsening pruritus and acute kidney injury. After admission, dermatology, rheumatology, and nephrology teams were consulted, and a skin and renal biopsy were obtained, with results significant for lupus erythematosus tumidus (LET), lupus nephritis grade III (not active), and IgA nephritis, consistent with a systemic lupus erythematosus exacerbation. Despite the patient's history of autoimmune disease, she had previously never received a biopsy for autoimmune hepatitis (AIH) during her initial diagnosis of cirrhosis. During her admission, an autoimmune hepatitis panel was obtained with results suggestive of autoimmune hepatitis; however, a conclusive diagnosis requires a liver biopsy, which was not obtained inpatient. In patients with a strong history of alcohol use, anchoring on substance use as the sole driver of liver disease may be easy, but this case highlights the importance of keeping a wide differential and considering related illnesses, even in patients with pre-existing diagnoses.

Lupus erythematosus tumidus (LET) is a rare form of cutaneous lupus erythematosus (CLE) with a controversial connection to systemic lupus erythematosus (SLE). We conducted a retrospective study with 34 LET patients in a Spanish tertiary referral center from 2007 to 2019. Most were women [52.9% (18/34)], with a median age of 53.5 years. Autoimmune or rheumatologic disorders were reported in 52.9% (18/34) of cases, and other CLE variants in 26.5% (9/34). SLE occurred in 8.82% (3/34), while 64.7% (22/34) had autoantibodies. Immunohistochemical CD123 testing tested positive in 75.9% (22/34), while direct immunofluorescence (DIF) showed positivity in 31.8% (7/22) of cases. Treatment included topical agents (100%), antimalarials (73.5%), oral corticosteroids (23.5%), and immunosuppressants (14.7%). All achieved clinical remission, but a delayed response (>3 months) was linked to SLE (p=0.002) and anti-DNA antibodies (p=0.003). LET usually associates with autoimmune disorders and autoantibodies. CD123 and DIF aid diagnosis, and systemic treatment may be needed, especially with SLE and anti-DNA antibodies.

While IL-23 inhibitors, which include guselkumab, tildrakizumab, and risankizumab, are currently FDA-approved solely for the treatment of psoriasis, several other inflammatory skin conditions have been associated with elevated IL-23 levels. The purpose of this review is to summarize and interpret the literature surrounding the off-label uses of IL-23 inhibitors in dermatologic practice. We conducted searches on PubMed and ClinicalTrials.gov for clinical trials, observational studies, case series, and case reports assessing use of the three IL-23 inhibitors for non-psoriatic dermatologic conditions. Conditions exhibiting promising response to treatment with IL-23 inhibitors include hidradenitis suppurativa, lichen planus, pityriasis rubra pilaris, pyoderma gangrenosum, dissecting cellulitis of the scalp, congenital ichthyosiform erythroderma, lichen planus pemphigoides, acrofacial vitiligo, lichen planopilaris, frontal fibrosing alopecia, lupus erythematosus tumidus, and Stewart-Treves angiosarcoma. Current literature suggests that IL-23 inhibitors may be effective in treating these conditions due to shared pathophysiologic pathways with psoriasis. Although these results are promising, further research through large-scale, randomized clinical trials is needed to further evaluate the efficacy and safety of IL-23 inhibitors in treating these off-label conditions.

Lupus erythematosus tumidus (LET) is a rare photosensitive dermatosis that is categorized as intermittent cutaneous lupus erythematosus. It shares clinical similarities and histopathological features with other skin disorders, such as erythema nodosum, lymphocytic infiltrate of Jessner, and reticular erythematous mucinosis, thus making diagnosis quite challenging. We present a patient with LET whose diagnosis was confirmed after seeing several doctors. A 52-year-old Hispanic female presented with tender erythematous nodules on her thighs for approximately 1 month. She was suspected of having erythema nodosum secondary to coccidioidomycosis and was prescribed fluconazole 200 mg for 30 days but showed no improvement. However, histopathological and direct immunofluorescence tests later confirmed a diagnosis of LET. The patient was treated with hydroxychloroquine, and the lesions improved remarkably after 2 weeks. LET is a rare dermatosis that closely resembles other dermatologic conditions such as erythema nodosum, lymphocytic infiltrate of Jessner, and reticular erythematous mucinosis. Diagnosis based on clinical features alone should be avoided, and ideally, treatment should only be initiated after confirmatory histopathological testing.