A tricolored dermatosis

Pigmentation disorder

Dr. Emmanuelle Bourrat

Saint-Louis Hospital

The clinical case
Now it's your turn!
Co-prescription and advice

Clinical case presentation

Following a prolonged period of bed rest, a young woman reported, at the beginning of her convalescence, several episodes of eruptions on the lower limbs occurring in the sitting or standing position, lasting about 15 minutes and regressing when lying down.
She also complained of chronic cyanosis of the lower limbs and dizziness when standing up. During one episode, clinical examination showed, on a background of cyanosis, erythematous, slightly papular patches surrounded by a halo of vasoconstriction, producing a “tricolored” dermatosis.

Your turn

What is your diagnosis?

Select 1 answer(s) from the following choices:

Cholinergic urticaria

Physiological livedo

BASCULE syndrome

Acrocyanosis

Wrong answer!

Good answer!

Diagnosis selected

This is BASCULE syndrome (Bier Anemic Spots, Cyanosis and Urticaria-Like Eruption), which is a benign vasomotor disorder. It mainly affects the lower limbs and is the result of exaggerated reflex arteriolar vasoconstriction triggered by orthostatic venous stasis, reflecting functional dysautonomia that is often transient.

It affects girls more than boys and has two peaks in frequency: early childhood and adolescence. Episodes sometimes have functional repercussions such as pruritus or painful paresthesia, but the symptom disappears quickly when lying down or walking. It is more rarely associated with a risk of syncope related to hypotension and/or postural orthostatic tachycardia, which must be systematically investigated in older children.

Explanation of incorrect answers

Cholinergic urticaria manifests as small, very itchy, edematous papules surrounded by an erythematous halo, appearing a few minutes after physical exertion or a hot shower and disappearing spontaneously within 30 to 60 minutes.
Livedo is characterized by a marbled pattern on the skin forming purplish networks that delimit areas of normal coloration. It is described as physiological when the networks are regular, closed, aggravated by cold and orthostasis and improved by heat.
Acrocyanosis is a benign vasomotor disorder common in underweight teenage girls, characterized by permanent purple discoloration of the extremities (hands and feet), which are cold and often clammy (hyperhidrosis).

Acrocyanosis and physiological livedo are often associated but do not involve papular lesions.

Treatment

The impact on quality of life is often moderate; otherwise treatment with antihistamines and venous compression can be proposed.

Expert's message

BASCULE syndrome, characterized by three elementary lesions (purple cyanosis, white vasoconstriction and pink papules), typically affects infants but also adolescent girls and young women.

References:

^{Kearns-Turcotte S, McCuaig C, Powell J, Piram M, Marcoux D, Hatami A, Coulombe J. Pediatric BASCULE syndrome in 42 patients: a peek into dysautonomia.}^{J Am Acad Dermatol.}^{2024 Sep 21:S0190-9622.}