Granular parakeratosis is an uncommon acquired keratinization disorder that occurs in the armpit, groin, and other parts of the body. It may be related to stimulation by detergents and antiperspirants. This article reports a case of granular parakeratosis in the groin. The patient was a young man with no predisposing factors. The clinical manifestations included symmetrical bilateral inguinal erythema, dryness, and a small amount of bran-like desquamation. After histopathological examination, the final diagnosis was granular parakeratosis, which was cured by topical application of glucocorticoid cream and silicone oil cream. Granular parakeratosis is a rare skin disease of unknown etiology. Clinicians need to pay attention to this disease and differentiate it from various diseases to avoid misdiagnosis.

Background Condyloma cuminata (CA) is a sexually transmitted disease caused by human papillomavirus (HPV) infection, which is prone to recurrence and difficult to cure in the short term. CD207 is a C-type lectin receptor that is specifically expressed on the surface of Langerhans cells (LCs) and is considered as an LC-specific immunohistochemical marker. The main purpose of this study is to explore the correlation between the expression of CD207 in CA skin lesions and the duration of CA disease course and frequency of recurrence, in order to provide new prognostic markers for CA to clinicians. Materials and Methods A total of 40 male patients with CA and their skin lesions were collected, as well as 40 healthy male penile tissue samples. The skin lesions of CA were clinically and histologically confirmed by acetic acid test. The expression of CD207 in epidermal tissues was detected using immunohistochemistry. The difference in the number of CD207 positive cells between CA skin lesions and healthy skin controls was compared, and the association between the number of CD207 positive cells in CA skin lesions and the duration of disease course and the frequency of recurrence was determined through Spearman correlation analysis. Conclusion In CA skin lesions, CD207 positive cells were found to have morphological abnormalities and the number of cells was significantly reduced compared to healthy skin, suggesting that there may be antigen presentation dysfunction in CA skin lesions, which may be the reason for the prolonged and unresolved condition of the disease. The fewer CD207 positive cells in CA skin lesions, the longer the disease course and the more frequent the recurrence, therefore, the expression level of CD207 can be used as a new prognostic marker for predicting the outcome of CA.

Mycobacterium marinum is an atypical bacterium, and skin infections caused by it are relatively rare, usually occurring in workers engaged in seafood processing and housewives who clean and prepare fish for consumption. The infection often occurs after the skin is punctured by fish scales, spines, etc. The JAK/STAT signaling pathway is closely related to the human immune response to infections. Therefore, JAK inhibitors may induce and exacerbate various infections in clinical practice. This article reports a case of mycobacterium marinum skin infection in the left upper limb of a female patient with chronic idiopathic myelofibrosis during treatment with ruxolitinib. The patient denied being punctured or scratched by fish scales or spines. Clinical manifestations included multiple infiltrative erythemas and subcutaneous nodules in the thumb and forearm. Histopathological examination showed infiltration of mixed acute and chronic inflammatory cells in the subcutaneous tissue. The diagnosis was ultimately confirmed by NGS sequencing. The patient was cured after taking moxifloxacin and clarithromycin for 10 months. Infection is a common adverse reaction of JAK inhibitors, but no literature has reported on mycobacterium marinum skin infections occurring during JAK inhibitor treatment, which is relatively rare. As the clinical application of JAK inhibitors becomes more widespread, the skin infections they cause may present in various forms and require the attention of clinicians.