Dermal melanocytosis is characterized by the presence of spindle-shaped melanocytes in the dermis. Common forms include Mongolian spots, nevus of Ota, nevus of Ito, and blue nevus. Nevus of Ota typically presents as bluish-brown patches involving the sclera and the cutaneous regions innervated by the ophthalmic and maxillary branches of the trigeminal nerve unilaterally. Blue nevus usually manifests as a solitary lesion. Agminated blue nevus is a rare variant that often presents as grouped, linear, or blaschkoid-distributed deep blue macules or papules. Only a few cases have reported the co-occurrence of nevus of Ota and agminated blue nevus. We herein report a case of extensive nevus of Ota combined with agminated blue nevus involving all three branches of the trigeminal nerve.

Reticulate acropigmentation of Kitamura (RAK) predominantly affects East Asian populations, though isolated cases and familial occurrences have been reported globally. Japanese researchers Kitamura et al. first described this condition in 1943. In 2013, pathogenic variants in ADAM10 (a disintegrin and metalloprotease 10) were identified as causative in multiple Japanese RAK pedigrees. The occurrence of RAK with Dowling-Degos disease (DDD) is relatively well-documented. However, rare associations with bilateral clinodactyly, nevus of Ito, dermatopathia pigmentosa reticularis, and progressive seborrheic keratosis have also been reported. RAK is an extremely rare autosomal dominant disorder. Café-au-lait macules (CALMs) represent common hyperpigmented lesions, yet no documented cases of RAK-CALMs coexistence exist in the literature to date.

Nevus spilus (NS) is a congenital melanocytic nevus with specific clinical characteristics. The condition generally appears in the first year of life and shows no gender preference while affecting individuals with lighter skin tones. It has a predilection for lower limbs and trunk areas the NS lesions consist of tiny heavily pigmented papules and macules accumulated on a well-bordered, lighter brown macular backdrop, comparable to a café-au-lait macule, frequently along Blaschko lines. The type of nevus has been reported as a blue nevus, centrofacial lentiginosis, nevus sebaceous, and bilateral nevus of Ito. To highlight laser options for nevus spilus. A review of various laser-based treatment modalities was conducted, focusing on their application in NS. The lasers included Q-switched ruby (QSRL), alexandrite (QSAL), Nd:YAG 532 and 1064 nm, carbon dioxide (CO2), intense pulsed light (IPL), and pulsed dye laser (PDL). The laser modalities have shown varying degrees of success in improving the appearance of NS lesions. The QSRL, QSAL and QSNYL lasers are commonly used because they are specific for melanin. Ablative lasers like CO2 and broad-spectrum devices like IPL and PDL have also been employed, each offering different advantages depending on lesion characteristics and treatment goals. Regular monitoring for suspicious malignant degeneration should be done and if any signs of melanoma are present, histological examination is warranted. While no treatment is usually necessary, surgery has been proposed to eliminate the risk of melanoma. Aside from surgical management, various lasers have been tried to treat NS with varied success. QSRL, QSAL, QSNYL 532, and 1064 nm, CO2, IPL and PDL have all been demonstrated to improve NS.

Nevus of Ito and Mongolian spots are distinct clinical presentations of patchy dermal melanocytosis, characterized by similar dermatological manifestations that can pose diagnostic difficulties for clinicians. This review aims to consolidate current understanding and research advancements on these conditions to facilitate clinical diagnosis, differential diagnosis, and management. A comprehensive search of databases including PubMed and Google Scholar was conducted, along with an analysis of pertinent literature retrieved from reference lists spanning nearly four decades. Epidemiological, clinical, and pathological profiles exhibit nuanced differences between the two conditions, with unique expressions under electron microscopy and the regression possibility. It is noteworthy that most Mongolian spots naturally fade with advancing age, in contrast to nevus of Ito, which persist and may potentially evolve into malignant lesions. While picosecond laser treatment has shown greater efficacy than nanosecond lasers, the lower-energy approach holds particular promise in pediatric cases. The therapeutic landscape for patchy dermal melanocytosis is evolving, shifting from selective photothermal action to photomechanical or subcellular photothermal modalities. This review underscores the importance of meticulous clinical assessment and the potential of innovative therapeutic approaches in managing these conditions. Nevus of Ota is a benign melanosis that primarily involves the region of the trigeminal nerve distribution. The first and second divisions of the trigeminal nerve, namely the ophthalmic V1 and the maxillary V2 are most commonly involved. There is associated hyperpigmentation of the eye. Nevus of Ota is also known as ocular dermal melanosis. The characteristic gray-blue hyperpigmentation occurs due to entrapped melanocytes. Unilateral presentation is more common. The melanocytes are entrapped leading to gray-blue hyperpigmentation of the conjunctiva and sclera along with ipsilateral facial skin. There is an increased risk of uveal melanoma and glaucoma in these cases. Palatal involvement may also occur.  Nevus of Ito is very similar to nevus of Ota except it differs in the territory of distribution. It was described by Minor Ota in 1954. It involves the distribution territory of lateral cutaneous brachial nerves of the shoulder and posterior supraclavicular nerves. Both of these diseases share similar pathophysiology.

Nevus of Ota, nevus of Ito and nevus of Hori are special melanocytic nevi that have a slate-brown or blue/grey coloring. They are pigmented disorders characterized by its heterotopic melanocytic dermal location and by blue/brown unilateral and sometimes bilateral facial patch in case of nevus of Ota, and in the supraclavicular, scapular, and deltoid region in case of nevus of Ito. It is more common in patients with Asian and dark-skinned ethnic backgrounds. Histologically, elongated, dendritic melanocytes are seen scattered mainly throughout the upper third of reticular dermis. An acquired variant is called Hori's nevus with more bilateral facial distribution, similar to melasma. Dermal melanocytosis can also occur elsewhere on the body, including inside the mouth. Despite its benign nature, patients frequently seek therapy because of its facial involvement. QS lasers are used effectively to treat these lesions. The number of treatment sessions correlates with clinical improvement. Post laser hypo- and hyperpigmentation are common side effects mainly affecting patients with darker skin.