Systemic vitamins K1 and K2 exhibit multifaceted functions beyond coagulation, particularly in pseudoxanthoma elasticum and similar conditions. Disturbances in the vitamin K pathway contribute to elastic fiber fragmentation and tissue mineralization. Systemic administration of vitamin K, notably via intramuscular injections, has been associated with a spectrum of adverse cutaneous reactions, from erythematous and eczematous plaques to drug-induced anetoderma and sclerodermoid plaques. The synergistic effect of vitamin K2 and vitamin D on bone mineralization has important implications for dermatologists who may counsel patients on supplementation with vitamins with sun-protective behaviors. In its topical form, vitamin K has been investigated for its wound healing properties, particularly in postlaser purpura resolution as well as prevention of cetuximab-induced dermatitis.

Cutis laxa (CL) is a rare connective-tissue disorder characterized by loose, inelastic skin due to defects in elastic fiber production or structure. Acquired cutis laxa (ACL) typically develops in adulthood and may follow inflammatory or immune-mediated events, though idiopathic cases remain uncommon. We report a 29-year-old male with a 10-year history of progressive skin laxity affecting the face, neck, and upper back. There were no preceding infections, drug exposures, or inflammatory skin conditions. Medical, surgical, and family histories were unremarkable. Examination revealed redundant, wrinkled skin with markedly reduced recoil in the involved areas, without joint hypermobility or systemic features suggestive of connective-tissue disease. Laboratory tests and imaging were normal. Histopathology demonstrated diminished and fragmented elastic fibers throughout the dermis, confirmed by Verhoeff-Van Gieson staining, consistent with ACL. This case represents an idiopathic, localized adult-onset form of ACL. The characteristic histological findings, along with the absence of systemic involvement, support the diagnosis. It is important to distinguish this condition from others, such as Ehlers-Danlos syndrome, anetoderma, and pseudoxanthoma elasticum, since overlapping clinical features can lead to misdiagnosis. Idiopathic ACL is rare and often under-recognized, and this case represents the first reported regional idiopathic instance, to the best of our knowledge, from Saudi Arabia. Overall, this case highlights the value of careful clinical assessment and histological evaluation in patients with slowly progressive, non-inflammatory skin laxity.

Anetoderma is a rare cutaneous disorder characterized by focal loss of dermal elastic tissue, often presenting as atrophic or herniated plaques. However, clinical presentations can vary, and atypical forms may resemble neoplastic or inflammatory lesions, complicating diagnosis. We present the case of a 78-year-old female who was evaluated for asymptomatic skin growths on the posterior neck, chest, and torso, reported to have been present for five years and slowly spreading. On physical examination, firm papules and subcutaneous nodules were noted on the left rib cage, left medial breast, and mid-trapezial neck. The lesions were initially diagnosed clinically as neoplasms of uncertain behavior, and two were biopsied using the punch method. Histopathology from the left rib cage revealed anetoderma, prompting reassurance and conservative management. At follow-up, anetoderma was also identified on the right medial superior chest. The patient remained asymptomatic, with no new lesions reported. This case highlights an uncommon presentation of anetoderma masquerading as subcutaneous neoplasms in an elderly patient with no known systemic disease or identifiable preceding dermatosis. It underscores the importance of histopathologic confirmation when evaluating lesions of uncertain behavior and expands the clinical spectrum of anetoderma, particularly in older adults. Given the lack of effective treatment options, accurate diagnosis is essential for guiding appropriate patient counseling and avoiding unnecessary interventions.

Anetoderma is commonly characterized by well-circumscribed areas of slack or baggy skin related to the loss of elastic fibers in the dermis. It has associations with some well-defined skin lesions, such as acne vulgaris and varicella. We report a 67-year-old woman with clinical and pathologically confirmed anetoderma at sites of previously documented lichen planus.

Dermatofibrosarcoma protuberans is an uncommon locally aggressive mesenchymal neoplasm that classically presents with a proliferation of monomorphic spindled cells with thin nuclei and scant cytoplasm. We report a man in his twenties who presented for an unrelated skin concern and was incidentally noted to have a large, atrophic scar-like depression of the left supraclavicular neck and shoulder. The plaque was photographed and the patient was instructed to follow-up in one year, and careful photo comparison revealed the lesion had subtly enlarged and darkened in color. Accordingly, a punch biopsy revealed features of myxoid dermatofibrosarcoma protuberans, a dermal proliferation of spindled cells with mucinous degeneration and more cellular areas with extensive nuclear palisading resembling the Verocay bodies of a neurofibroma. Clinicians should be aware of the broad clinicopathologic spectrum of DFSP to ensure timely diagnosis and effective treatment. Myxoid dermatofibrosarcoma protuberans is a rare and clinically challenging diagnosis, as the mucinous areas can impart a bluish hue. Dermatofibrosarcoma protuberans can also be atrophic, with the loss of the normal dermal thickness corresponding to a clinical appearance easily mistaken for anetoderma or atrophic scar. Palisaded nuclei resembling the Verocay bodies of schwannoma are sometimes seen and can further obfuscate the diagnosis.

Striae, or stretch marks, are a common complaint and can be distressing. They may affect the abdomen, buttocks, thighs, breasts, back, axillae and groin. They are classified according to appearance or epidemiology, as: striae atrophicans (thinned skin); striae gravidarum (following pregnancy); striae distensae (stretched skin); striae rubrae (red), striae albae (white); striae nigra (black); striae caerulea (dark blue).  Striae are difficult to treat effectively. [1][2]

The term anetoderma is derived from the Greek words 'anetos', meaning relaxed, and 'derma,' meaning skin. The condition was first described by Jadassohn in 1892. Anetoderma is a benign disorder of elastolysis, causing well-circumscribed, focal areas of flaccid skin. The localized areas of slack skin can present clinically as round to oval atrophic depressions, wrinkled macules, patches, or herniated sac-like protrusions with a surrounding border of normal skin. The lesions can be a variety of colors from skin-colored, white, grey, brown, or blue, and the size can range from millimeters to centimeters. Anetoderma most commonly presents on the trunk and proximal extremities. Once present, the disease tends to be active for at least 15 years. No reports of spontaneous regression have occurred.

Anetoderma is an uncommonly reported dermatosis clinically characterized by discrete skin lesions resulting from elastic fiber loss within the dermis. Although primary anetoderma has been considered idiopathic, a range of associated disorders, particularly prothrombotic abnormalities, have been reported. We present a 79-year-old woman with a heterozygous Factor V Leiden mutation who developed anetoderma shortly after COVID-19 infection complicated by a thromboembolic event. Our patient adds to the literature on the occurrence of anetoderma in the setting of infection and/or a prothrombotic disorder.