Interstitial mycosis fungoides: A rare presentation of mycosis fungoides with overlapping granulomatous and folliculotropic features

BACKGROUND

Interstitial mycosis fungoides (IMF) is a rare subtype of mycosis fungoides (MF) characterized by atypical lymphocytes infiltrating the reticular dermis between collagen bundles with limited epidermotropism and variable granulomatous features.

METHODS

Retrospective single institution review of 31 cases of IMF including clinical characteristics, disease course and pathological features.

RESULTS

Our cohort was predominately male (19; 61%, M:F 1.6:1) with a mean age at diagnosis of 43 years (range 11-85), mean signs/symptoms duration of 7 years prior to diagnosis, and 6 years mean follow-up duration. Clinically, patients often exhibited symmetric ill-defined patches/plaques involving intertriginous regions with tan-yellow hyperpigmentation and follicular-based papules, wrinkling, and alopecia. Lymphadenopathy was noted in seven patients. Fifteen (52%) patients were in near or complete clinical remission at the latest follow-up. T-cell receptor gene rearrangement was positive in 23/24 (96%) cases. Histopathologically, atypical cells were small-medium, CD4+ (29; 94%) or rarely CD4+/CD8+ (1; 3%) lymphocytes infiltrating the reticular dermis with thickened collagen bundles (27; 87%), multinucleated giant cells (12; 39%), and often tracing along adnexa with subtle folliculotropism (12/20; 60%).

CONCLUSIONS

Our study demonstrates IMF is an indolent subtype of MF with distinct features, including frequent granulomatous and subtle follicular involvement resulting in alopecia.

Recurrent inverse necrotizing infundibular crystalline folliculitis

Necrotizing infundibular crystalline folliculitis (NICF) is a rare type of necrotizing folliculitis. The disease typically manifests as folliculocentric papules arising in a seborrheic distribution. Only 23 cases exist in the literature. Most reported cases have arisen spontaneously, but a small number of drug-induced cases in the setting of epidermal-derived growth factor, vascular endothelial-derived growth factor, or PD-1 inhibitor therapy have been reported. Colonization by bacteria and/or yeast occurs frequently. The etiology remains unknown, but some suggest a complex interplay with an aberrant microbiome, sebaceous gland dysfunction, and perturbed EGFR signaling in follicular infundibula. Histopathologic findings include rupture of follicular epithelium, neutrophilic inflammation, and nodular cup-shaped crystal deposits. We present a case of spontaneous, recurrent NICF in an inverse pattern in the inguinal region.

Lichen Planus Pigmentosus Inversus: A Case Report of a Man Presenting With a Pigmented Lichenoid Axillary Inverse Dermatosis (PLAID)

Lichen planus pigmentosus is an uncommon subtype of lichen planus and lichen planus pigmentosus inversus is a rare variant of lichen planus pigmentosus. Lichen planus pigmentosus inversus typically presents as hyperpigmented patches or plaques, particularly in the intertriginous areas such as the axillae, the groin and inguinal folds, and in the submammary region. In some patients with lichen planus pigmentosus inversus, the condition can present as a pigmented lichenoid axillary inverse dermatosis (PLAID) when the lesions are in the axillae. A 49-year-old Hispanic man who had hyperlipidemia and diabetes mellitus developed lichen planus pigmentosus inversus and presented with a PLAID. Skin biopsies established the diagnosis of lichen planus pigmentosus inversus. The clinical differential diagnosis of lichen planus pigmentosus inversus includes inherited disorders, primary cutaneous dermatoses, acquired dyschromias, and reactions to topical or systemic medications. Friction in intertriginous areas has been related to the development of lichen planus pigmentosus inversus. Factors that can precipitate lichen planus pigmentosus inversus include not only topical exposure to almond oil, amala oil, cold and cosmetic creams, henna, and paraphenyldiamine but also either topical contact or consumption of mustard oil and nickel. Lichen planus pigmentosus inversus can be associated with autoimmune conditions (hypothyroidism), endocrinopathies (diabetes mellitus), and hyperlipidemia. The dyschromia found in patients with lichen planus pigmentosus inversus is frequently refractory to treatment. Initial management includes removal of potential disease triggers such as eliminating tight clothing to stop friction with the adjacent skin. Topical corticosteroids do not result in improvement; however, topical calcineurin inhibitors such as tacrolimus have been reported to be efficacious. In conclusion, inverse lichen planus and lichen planus pigmentosus inversus can present with a PLAID; whereas topical corticosteroids may be helpful to resolve inverse lichen planus lesions, topical tacrolimus may be useful to improve the dyschromia in lichen planus pigmentosus inversus.

Underdiagnosed and undertreated psoriasis: Nuances of treating psoriasis affecting the scalp, face, intertriginous areas, genitals, hands, feet, and nails

Psoriasis of the scalp, face, intertriginous areas, genitals, hands, feet, and nails is often underdiagnosed, and disease management can be challenging. Despite the small surface area commonly affected by psoriasis in these locations, patients have disproportionate levels of physical impairment and emotional distress. Limitations in current disease severity indices do not fully capture the impact of disease on a patient's quality of life, and, combined with limitations in current therapies, many patients do not receive proper or adequate care. In this review, we discuss the clinical manifestations of psoriasis in these less commonly diagnosed areas and its impact on patient quality of life. We also examine clinical studies evaluating the effectiveness of therapies on psoriasis in these regions. This article highlights the need to individualize treatment strategies for psoriasis based on the area of the body that is affected and the emerging role of biologic therapy in this regard.

Evidence and Suggested Therapeutic Approach in Psoriasis of Difficult-to-treat Areas: Palmoplantar Psoriasis, Nail Psoriasis, Scalp Psoriasis, and Intertriginous Psoriasis

Psoriasis is resistant to treatment and it shows frequent relapse; systemic treatment is often associated with toxicities, and long-term safety data are lacking for most of the newer drugs like biologics. Moreover, some body areas such as hands, feet, intertriginous areas, scalp, and nails are even more resistant. Frequently, systemic treatments are necessary considering the higher psychological impact on the patient. There is a lack of agreement on the best therapeutic modalities in the management of psoriasis involving difficult-to-treat locations. At present, there are no Indian guidelines for these conditions. Available literature has been reviewed extensively on the treatment of psoriasis involving difficult-to-treat locations; level of evidence has been evaluated as per the Oxford Centre for Evidence-Based Medicine 2011 guideline, and therapeutic suggestions have been developed. Best care has been employed to consider socioeconomic, cultural, genetic, and ethnic factors to prepare a therapeutic suggestion that is appropriate and logical to be used among Indian population and people of similar ethnic and socioeconomic background.