Generalized Eruptive Histiocytosis or Juvenile Xanthogranuloma: A Clinicopathological Conundrum of Coexistence or Xanthomatization.

Diseases under the non-Langerhans cell histiocytosis (LCH) group often share clinical and histological similarities, making proper delineation highly challenging. A two-year-old female child presented with multiple, small raised asymptomatic lesions all over the body for one year. Cutaneous examination showed multiple brownish flat-topped and yellowish-brown dome-shaped papules scattered all over the body with hyperpigmented macules over the face. A provisional diagnosis of generalized eruptive histiocytosis (GEH) was made. But the dermoscopy and histopathological examination of flat-topped and dome-shaped papules showed features suggestive of generalized eruptive histiocytosis and juvenile xanthogranuloma (JXG) respectively, with a few overlapping features. Systemic examination was found to be normal. Hence an overlap of GEH and JXG was considered, with a thought of ongoing xanthomatization of GEH lesions. The transformation of GEH into xanthoma disseminatum, multicentric reticulohistiocytosis, progressive nodular histiocytosis, and juvenile xanthogranuloma (JXG) has been reported. It has also been reported that GEH and JXG, the two entities that belong to a continuous spectrum of histiocytoses with xanthogranulomatous pathology, can rarely co-exist in the same individual. The distinction between GEH and JXG is crucial, as they may require different management strategies. Our case stresses the fact that relying only on clinical diagnosis can be deceiving owing to the overlapping clinical, dermoscopic, and histopathological features of histiocytoses.

Aluminium in dermatology - Inside story of an innocuous metal.

Aluminium, the third most abundant element in the earth's crust, was long considered virtually innocuous to humans but has gained importance in the recent past. Aluminium is ubiquitous in the environment, with various sources of exposure like cosmetics, the food industry, occupational industries, the medical field, transport and electronics. Aluminium finds its utility in various aspects of dermatology as an effective haemostatic agent, anti-perspirant and astringent. Aluminium has a pivotal role to play in wound healing, calciphylaxis, photodynamic therapy and vaccine immunotherapy with diagnostic importance in Finn chamber patch testing and confocal microscopy. The metal also finds significance in cosmetic procedures like microdermabrasion and as an Nd:YAG laser component. It is important to explore the allergic properties of aluminium, as in contact dermatitis and vaccine granulomas. The controversial role of aluminium in breast cancer and breast cysts also needs to be evaluated by further studies.

Dyschromatosis universalis hereditaria.

Reticulate pigmentary dyschromatoses primarily include dyschromatosis universalis hereditaria (DUH), dyschromatosis symmetrica hereditaria (DSH) (Reticulate acropigmentation of Dohi), and unilateral dermatomal pigmentary dermatosis, which differ in their patterns of distribution. The disease was initially described by Ichikawa and Hiraga in Germany in 1933. The prevalence of DUH is 0.3 per 100,000 with a female preponderance. The skin lesions usually appear in infancy or early childhood and cease to progress beyond adolescence. The subtypes DUH 1 and DUH 3 are found to have autosomal dominant inheritance, which is the most common inheritance pattern, while DUH 2 has an autosomal recessive pattern. The most common gene involved in DUH is ABCB6, while the other genes include SASH 1, PER 3, and KITLG (DUH type 2). DUH is characterized by multiple irregular hyperpigmented macules interspersed with hypopigmented macules in a mottled pattern over the trunk and extremities. The face is involved in 50% of individuals. Rarely, it can also involve hairs, nails, mucous membranes, palms, and soles. Other varied presentations include localized forms, localization of lesions to sun-exposed areas, large macules, uniform palmar hypopigmentation, diffuse hyperpigmentation with spotty depigmented macules, and unilateral involvement. DUH has been reported to be associated with various cutaneous and systemic diseases. The authors have observed cases of DUH associated with hepatocellular carcinoma, solitary keratoacanthoma, and dermoid cyst. The various diagnostic modalities include dermoscopy, histopathology, electron microscopy, and targeted gene sequencing. Though various treatment modalities like NBUVB and lasers have been tried, no treatment is promising.

Dermatological adverse effects of hair dye use: A narrative review.

Hair dyeing is a popular practice dating back to ancient Egyptian times. Initially, hair dye use was restricted to concealing grey and white hairs of the elderly population. However, in recent times, its use is common among the younger generation as a fashion statement. Hair dye contact dermatitis is a common dermatological condition encountered by dermatologists. It is a delayed type of hypersensitivity reaction that commonly affects the scalp and the vicinity of hair line and neck. Para-phenylenediamine (PPD), a synthetic aromatic amine is the most common allergen specifically implicated in hair dye contact dermatitis. Para-phenylenediamine was announced as the allergen of the year in 2006 by the American Contact Dermatitis Society. Contact allergy to para-phenylenediamine can occur in 0.1-2.3% of the general population. Epicutaneous patch testing is the gold standard test for the diagnosis of hair dye contact dermatitis. However, para-phenylenediamine carries a risk of cross-sensitivity and co-sensitization to other allergens. Apart from contact dermatitis, hair dye use is also associated with various other cutaneous adverse effects such as pigmentary changes, hair loss, skin malignancies and autoimmune disorders. Due to the various adverse effects associated with hair dye use, it is prudent to look for safer alternatives to allergenic hair dyes. In this article, we review the epidemiology, cutaneous and systemic adverse effects associated with hair dye use, patch testing, preventive strategies to minimize the risk of hair dye contact dermatitis, and treatment aspects.

Pitted keratolysis.

Pitted keratolysis (PK) is a common superficial bacterial skin infection confined to the stratum corneum. It is clinically characterized by multifocal, discrete, pits or crater-like punched-out lesions, commonly over the pressure-bearing aspects of the foot. It is asymptomatic and associated with malodour. The surface is often moist and macerated. The diagnosis of PK is often clinical and diagnostic procedures are usually unnecessary. Lifestyle modifications form the cornerstone of the management of PK. It responds well to topical antimicrobials.

Acquired Fibrokeratoma: A Retrospective Study in a Tertiary Centre in South India.

Background: Acquired fibrokeratoma (AFK) is an uncommon, sporadic, benign, acquired, slow-growing dermo-epidermal tumour. Aims and Objectives: The purpose of this study was to summarize the demographic, clinical characteristics and treatment outcomes of patients with AFK in a tertiary care centre in South India. Methods: We evaluated the records of 26 patients with AFK who were diagnosed and treated in our centre between January 2017 and December 2021. The retrospective data related to age, sex, occupation, consistency, duration of lesions, history of trauma, anatomical site, morphological appearance, histopathological type, treatment provided and recurrence were taken into account and analysed. Results: Of the 26 patients, there were 21 males and 5 females. Fingers (n = 23) were the most common site involved, followed by toes (n = 2) and palm (n = 1). A total of 18 patients had finger-like projected lesions and eight patients had dome-shaped lesions. In histopathology, Type I AFK type was observed in 16 cases and Type II in 10 cases. Conclusion: We believe that our study would contribute by providing the clinical, histopathology and treatment outcomes of this uncommon dermo-epidermal tumour. The frequency of this condition is often underestimated as it is misdiagnosed for many other dermatological conditions.

Papulonecrotic tuberculid.

Papulonecrotic tuberculid (PNT) is an uncommon form of id eruption, which occurs in association with tuberculosis infections in patients with a high degree of immunity and allergic sensitivity to mycobacterial organisms. It commonly presents as recurrent crops of papulonecrotic lesions that crust or ulcerate, and heal with atrophic varioliform scars over time. The differential diagnoses of PTN are wide and varying. Tuberculin test is usually strongly positive. Histology shows tuberculoid histology with endarteritis and thrombosis of dermal blood vessels. One of the hallmarks of PNT is its prompt response to antituberculous therapy. The purpose of this article is to increase awareness of this condition among dermatologists.

Bowen's Disease.

Bowen's disease (BD) is an in-situ squamous cell carcinoma of epidermis. The etiology of BD is multifactorial with high incidence among Caucasians. BD is common in photo-exposed areas of skin, but other sites can also be involved. Lesions are usually solitary. The morphology of BD differs based on age of the lesion, site of origin, and the degree of keratinization. BD is considered as the "lull before the storm," which precedes an overt squamous cell carcinoma. Histopathology is the gold standard diagnostic modality to confirm the diagnosis. Immunohistochemistry, dermoscopy, and reflectance confocal microscopy are the adjuvant modalities used in the diagnosis of BD. The treatment depends on various factors like site, size, immune status, patient's age, esthetic outcome, etc. The available therapeutic modalities include topical chemotherapy, surgical modalities, light-based modalities, and destructive therapies. It requires a combined effort of dermatologist, oncosurgeon, and plastic surgeon to plan and execute the management in various presentations of BD.