Lichen striatus in adults or 'adult blaschkitis'? There is no need for a new naming

Adult Blaschkitis With Lichenoid Features and Blood Eosinophilia

There have been many reports of congenital and acquired dermatoses that trail Blaschko lines. Lichen striatus is representative of an acquired cutaneous linear inflammatory dermatosis running along the lines of Blaschko, characterized histopathologically by the predominance of lichenoid infiltration. Adult blaschkitis, however, is considered under the same disease spectrum as lichen striatus and is characterized by a spongiotic reaction pattern. Few differences have been recognized between lichen striatus and adult blaschkitis such as age of onset, triggers, distribution, histopathology, and response to treatment.

A case of male patient with adult blaschkitis presenting as unilateral asymptomatic erythematous edematous papules, papulovesicles, and plaques over Blaschko’s lines, in which skin biopsy revealed coexistent pathological features of lichen striatus and adult blaschkitis along with blood eosinophilia, has been presented here. This may add to the cumulative evidence on the pathogenesis of adult blaschkitis as an allergic reaction to an unknown inciting allergen.

Evidence to consider adult blaschkitis as part of the lichen striatus spectrum is growing. Triggers for such skin reactions remain diverse. This case presentation suggests that adult blaschkitis could be triggered by an allergic response evidenced by the blood eosinophilia when other causes of eosinophilia are excluded.

Lichen planus and other lichenoid dermatoses: Kids are not just little people

Lichenoid dermatoses, a group of inflammatory skin conditions with characteristic clinical and histopathologic findings, range from common to rare. Classic lichen planus typically presents as pruritic, polygonal, violaceous flat-topped papules and plaques; many variants in morphology and location also exist. Other lichenoid dermatoses share similar clinical presentations and histopathologic findings. These include lichenoid drug eruption, lichen planus-like keratosis, lichen striatus, lichen nitidus, and keratosis lichenoides chronica. Epidemiologic characteristics vary among each lichenoid disorder. While classic lichen planus is considered a disease of adults, other lichenoid dermatoses may be more common in younger populations. The literature contains an array of reports on the variations in presentation and successful management of lichen planus and lichenoid dermatoses among diverse populations. Familiarity with the characteristics of each lichenoid dermatosis, rare or common within each patient population, is key to accomplishing timely recognition and effective management.

Lichen striatus: after a bite by bumblebee

Lichen striatus (LS) is an uncommon dermatosis characterised by a linear inflammatory papular eruption. It is frequently seen in children and rarely in adults. We present in this study a 49-year-old female patient who was diagnosed as LS, which occurs after a bite by bumblebee. As we know, it is the first case of LS reported after a bite by bumblebee.

Lichen striatus on adult

Lichen Striatus is an uncommon inflammatory skin eruption of unknown etiology. It rarely affects adults, and it is characterized by abrupt onset of coalescent papules, in a linear disposition, usually on the extremities. Histopathology shows lichenoid reaction involving follicles and glands. Occasionally, there is overlap with linear lichen planus and "blaschkitis", the main differential diagnoses. It is reported here the case of an adult woman with erythematous violaceous papules on the right side of the neck and face, diagnosed with lichen striatus by clinical and histopathological correlation. The atypical findings and the diagnostic difficulty are discussed.

Blaschkitis in children - a new entity?

Blaschkitis is an acquired, rare dermatitis that follows the lines of Blaschko. Many consider blaschkitis as a variant of lichen striatus, although authors felt that it is a separate entity. A 2½-year-old girl presented with multiple grouped papules along the lines of Blaschko on her trunk. The main differences to lichen striatus are illustrated. Our case supports the hypothesis that blaschkitis is an entity of its own.

Lichen striatus in adults and pimecrolimus: open, off-label clinical study

BACKGROUND

Lichen striatus is a well-known, acquired, self-healing, linear inflammatory dermatosis. Lichen striatus occurring in adults tends to be more extensive and itchy than in children, sometimes requiring symptomatic treatment. The therapeutic approach usually adopted is topical steroids, even though prolonged use may lead to several side-effects, particularly cutaneous atrophy.

OBJECTIVE

To report the results of an open, off-label study on the use of pimecrolimus 1% in the treatment of diffuse, nonresponsive forms of lichen striatus.

METHODS

Three adult patients suffering from relapsing or disseminated and itchy lichen striatus received topical application of pimecrolimus 1% cream (Elidel, Novartis Pharma, Basle, Switzerland) twice daily for 6 weeks, or until complete disappearance of the cutaneous lesions.

RESULTS

All patients experienced rapid healing of the dermatosis, without any recurrence for at least 14 months.

CONCLUSION

Our preliminary results show that pimecrolimus may represent a useful therapeutic alternative for lichen striatus, although further studies on a larger number of cases are needed to confirm its safety and efficacy in the treatment of this condition.

"Pediatric blaschkitis": expanding the spectrum of childhood acquired Blaschko-linear dermatoses

We describe two young children who developed relapsing, pruritic, papulovesicular eruptions in multiple bands along Blaschko lines on the neck, trunk, and extremities. Skin specimens in both revealed spongiotic dermatitis. This represents the first report of "blaschkitis" in children, providing further evidence that lichen striatus and blaschkitis are related acquired Blaschko-linear dermatoses that exist on a spectrum rather than as the childhood and adult form of a single disease entity. We highlight the features that differentiate blaschkitis from lichen striatus, review the potential roles of cutaneous mosaicism, environmental triggers, and background immunologic state in their pathogenesis, and discuss the spectrum of inflammatory dermatoses that can follow Blaschko lines.

Lichen striatus in an adult following trauma

A 36-year-old man presented with a linear erythematous eruption along his right forearm and dystrophy of his right thumbnail. These changes had developed 2 weeks after his right thumb had been pricked by a pineapple leaf and evolved over a 6-week period. Histopathology revealed features consistent with lichen striatus. He complained of mild intermittent pruritus, which responded to moderate-potency topical corticosteroids. At 12 months the skin eruption had improved, but the nail changes persisted.