Moulin's linear atrophoderma (LAM) is a rare acquired pigmentary atrophic dermatosis distributed along Blaschko's lines, with an unclear etiology and poorly understood pathogenesis. This report presents two cases of LAM. Both patients were male, with onset during adolescence. Notably, one patient exhibited elevated antinuclear antibody (ANA) levels (1:320). Histopathological examination of both cases revealed a generally normal or mildly hyperplastic epidermis, hyperpigmentation of the basal layer, and a mixed inflammatory cell infiltrate (predominantly lymphocytes) in the dermis. Based on their clinical presentation and histopathological findings, both patients were diagnosed with LAM.

The findings in EBP-related X-linked chondrodysplasia punctata (EBP-CDPX) range from fetal demise with multiple malformations and severe growth deficiency to much milder manifestations, including females with no recognizable physical abnormalities. At least 95% of live-born individuals with EBP-CDPX are female. Characteristic features include growth deficiency; distinctive craniofacial appearance; chondrodysplasia punctata (stippling of the epiphyses of the long bones, vertebrae, trachea, and distal ends of the ribs); often asymmetric rhizomelic shortening of limbs; scoliosis; linear or blotchy scaling ichthyosis in the newborn; later appearance of linear or whorled atrophic patches involving hair follicles (follicular atrophoderma); coarse hair with scarring alopecia; and cataracts.

Atrophoderma of Pasini and Pierini is a rare, cutaneous condition that causes dermal atrophy. Pasini described it in 1923 under the name of ”progressive idiopathic atrophoderma.” Pierini and Vivoli later further described it in 1936, suggesting its possible link to morphea. It presents as single or multiple, sharply demarcated, hyperpigmented, non-indurated patches with no obvious inflammatory signs.

We report a rare case of Blau syndrome in a 1-year-old boy. The patient presented with characteristic facial manifestations, notably skin lesions exhibiting atrophoderma vermiculates-like appearance; ocular and articular symptoms were notably absent at presentation. Histopathological examination confirmed non-caseating granulomatous inflammatory changes. Whole-genome sequencing (WGS) identified a heterozygous pathogenic mutation (p. Arg307Trp) in the nucleotide oligomerization domain 2 (NOD2) gene. Treatment with oral prednisone combined with topical vitamin E application resulted in a significant improvement of his skin lesions.

Epidermolysis bullosa simplex (EBS) with cardiomyopathy is a rare subtype caused by gain-of-function pathogenic variants in the KLHL24 gene, leading to both skin and cardiac involvement. We report a neonate with congenital erosions, scarring, and follicular atrophoderma, but minimal blistering, later confirmed to have a pathogenic KLHL24 variant. This presentation highlights atypical neonatal features that may mimic other conditions and emphasizes the importance of early genetic diagnosis. Given the risk of dilated cardiomyopathy, ongoing cardiac monitoring and family evaluation are essential.

We report a 70-year-old man with a long-standing history of eruptive syringomas, including scattered plaque-type syringomas that raised clinical concern for basal cell carcinoma. A biopsy of a plaque-type lesion on the left clavicle revealed a syringoma with superficial follicular infundibular cysts resembling those of microcystic adnexal carcinoma (MAC). The lesion also exhibited cords and trabeculae streaming from the epidermis, and solid nests of variable sizes extending to the deep dermis, reminiscent of the solid variant of MAC. Excision revealed a fairly circumscribed tumor within a sclerotic stroma that did not invade nerve or infiltrate fat, supporting a diagnosis of plaque-type syringoma. Additional lesions have since been biopsied, revealing similar findings, but none of them have been re-excised nor have they recurred. The patient had facial milia, but was not thought to have Nicolau-Balus syndrome given the absence of atrophoderma vermiculata and a lack of a pertinent family history. Herein, we discuss the histomorphologic diversity of syringomas and helpful findings that distinguish them from carcinoma. An unequivocal distinction between syringoma and MAC is not always feasible on a partial sample, but awareness of rare syringoma variants can sometimes prevent unnecessary surgery.

Smooth muscle hamartoma (SMH) is a benign cutaneous tumor that typically presents at birth as a solitary lesion in the lumbosacral region. Acquired cases with multiple lesions and subtle depression are exceedingly rare. We report a 40-year-old male with a seven-year history of multiple pigmented macules with slight depression on the trunk and extremities. Histopathology of a back lesion revealed irregularly distributed bundles of pale eosinophilic smooth muscle fibers in the upper dermis, positive for α-smooth muscle actin (α-SMA). Basal hyperpigmentation was observed, without swelling of collagen fibers or atrophic eccrine glands. Differential diagnoses such as Becker's nevus and atrophoderma of Pasini and Pierini were excluded based on clinical and histological findings. Taken together, the patient was diagnosed with SMH. Although excision may be considered for solitary lesions, it was not performed in our patient due to multiple lesions. No progression was observed over two years of follow-up. This case illustrates a unique acquired SMH with multiple lesions and depressed appearance, emphasizing the importance of recognizing this entity in the differential diagnosis of multiple pigmented macules in adults.

The rare atrophoderma of Pasini and Pierini (APP) is most commonly attributed to the disease spectrum of morphea, alongside atrophoderma Moulin. We report the case of a young woman with an unusually extensive presentation of APP, which partially exhibited a blaschkoid pattern. The clinically unobservable atrophy of the corium could be confirmed using an additive diagnostic procedure with 12 MHz ultrasound.

We report a young child who presented with atrophic reticulated depressions with ipsilateral cataracts, suggesting that this could represent a distinct and rare entity.

Atrophoderma of Pasini and Pierini is a rare skin disease that presents with dermal atrophy. Differentiating this condition from morphea remains a challenge. Etiology is unknown, and there is no effective treatment till date. The diagnosis is made through clinicohistopathological correlation.

A 12-year-old female presented with multiple milia and skin-coloured papules over face and neck, follicular atrophoderma and hypotrichosis. Family history of similar complaints present in mother and maternal aunt. Biopsy from the skin-coloured papule revealed trichoepithelioma. Multiple milia, hypotrichosis and follicular atrophoderma favour the diagnosis of Bazex-Dupre-Christol syndrome (BDCS) which is an X-linked dominant genodermatosis with BCCs developing later in life. Other conditions with multiple BCCs and milia like Gorlin syndrome, Oley syndrome and Rombo syndrome should be differentiated. Follicular atrophoderma and hypotrichosis with X-linked dominant inheritance favour the diagnosis of BDCS. Management should focus on identifying BCCs at the earliest and genetic counselling.

Bazex-Dupré-Christol syndrome is a rare genetic condition characterised by basal cell carcinomas, follicular atrophoderma and hypotrichosis. Until recently, the molecular basis of the condition was largely unknown. A recent study has identified a section of duplicated DNA on the X chromosome of those with the condition which appears to be the underlying cause of the syndrome. This case study looks at a family with five affected members over three generations. They had been diagnosed with the syndrome in early life and had previously undergone genetic testing with no cause being found. The index patient within this family has now been identified as having the same duplication as those tested in the initial study.

Atrophoderma of Pasini and Pierini (APP) is a rare skin condition of unknown etiology. It is characterized by dermal atrophy with single or multiple hyperpigmented, non-indurated, and slightly depressed plaques on the trunk or limbs; unlike morphea, this condition does not cause induration. In this report, we analyze the case of a patient diagnosed with APP with a 19-year history of progression, aiming to highlight the few cases published in the literature. The patient responded favorably to treatment with mycophenolic acid (MPA). Therapeutic approaches for this condition are controversial due to its long-term progression and low frequency. Currently, there are no published reports on the use of MPA for the treatment of this condition.

Cutaneous atrophy resulting from corticosteroid injections for musculoskeletal indications is an underrecognized adverse effect among orthopedists and dermatologists. We present two cases of cutaneous atrophy following corticosteroid injections for wrist tendonitis. Patients presenting with cutaneous atrophy following orthopedic corticosteroid injections may be misdiagnosed with linear morphea, atrophoderma, or vascular disorders and receive unnecessary workups and delays in appropriate management. Dermatologists play an essential role in the evaluation of these patients.