CASE #2: Telangiectasia macularis eruptiva perstans

Also referred to as paucicellular mastocytosis, telangiectasia macularis eruptive perstans (TMEP) is just one of several forms of cutaneous mastocytosis. The other variants include urticaria pigmentosa, maculopapular cutaneous mastocytosis, diffuse cutaneous mastocytosis, mastocytoma of the skin, and erythrodermic mastocytosis. Cutaneous mastocytosis is an uncommon cause of skin disease.

The epidemiology of TMEP has yet to be fully defined. While urticaria pigmentosa, the most common of the cutaneous mastocytoses, is common in children, TMEP is very rare in children. Familial TMEP has been reported and can occur in children. In the United States, 0.1%-0.8% of new patients seeking care in dermatology clinics have some form of mastocytosis. Less than 1% of patients visiting dermatology clinics with mastocytosis have TMEP.

The physical manifestations of TMEP include telangiectases measuring 2-6 mm, sometimes on a background of erythema or tan discoloration. TMEP represents permanent vasodilation of the skin, secondary to mast-cell release of chemical mediators and angiogenic factors. TMEP most commonly involves the trunk but has been reported in rare instances to occur unilaterally. Heat and pressure may produce localized urticaria.


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TMEP rarely has systemic complications. Most patients complain only of variable degrees of pruritus. Darier’s sign, a wheal surrounded by erythema in an area of skin with mast cells, is almost always present in urticaria pigmentosa but may not be present in TMEP. Rare cases of TMEP are associated with episodic headaches, flushing, GI upset, palpitations, syncope, hepatosplenomegaly, increased numbers of mast cells in the bone marrow, and abnormal findings on skeletal radiographs.

The differential diagnosis of TMEP includes essential generalized telangiectases (those simply present since birth), nevoid telangiectases, telangiectases due to liver disease, carcinoid syndrome rosacea, carcinoid syndrome, hepatopathy or collagenosis, and hereditary hemorrhagic telangiectasia. TMEP manifesting as a pseudoallergic food reaction has been reported.1 One woman presented late in the second trimester with an anaphylactoid reaction, rash of blood vessels, uterine contractions, and vaginal bleeding.2 The patient had a markedly elevated urinary histamine level, and skin biopsy revealed perivascular mast-cell infiltration, establishing the diagnosis of TMEP. She was treated successfully with tocolytics and antihistamines.

The histologic findings of TMEP involve mast cells surrounding capillary venules and the superficial venular plexus. Mast cells have a “fried egg” appearance and can be definitively detected with Giemsa, toluidine blue, chloroacetate esterase, and aminocaproate esterase stains, which are picked up by metachromatic cytoplasmic granules. On occasion, the mast cells are somewhat sparse, complicating the pure histologic establishment of a diagnosis and necessitating clinicopathologic correlation.

TMEP associated with malignant melanoma was reported in 2009, but no role for TMEP as a marker of malignancy has yet been established. Mutations in the c-kit (mast cell growth factor) proto-oncogene are not found in all patients with cutaneous mastocystosis. Alterations in this proto-oncogene may indicate more aggressive mastocytosis and have been observed in melanoma but not TMEP. 

Although TMEP is a cutaneous manifestation of mastocytosis, systemic involvement may occur. Elevated serum tryptase levels may serve as a guide for systemic involvement. In a study of 52 patients, the prevalence of bone-marrow biopsy specimens indicating systemic mastocytosis rose as the level of total tryptase increased. The biopsy specimens were 100% positive when total tryptase was >75 ng/mL and 50% positive when total tryptase levels were 20-75 ng/mL.3

Treatment of TMEP, if it is symptomatic, involves H1- receptor antagonists, such as hydroxyzine, to help reduce pruritus or flushing. The 585-nm flashlamp-pumped dye laser, which targets blood vessels, has yielded some success. Pre-laser treatment with appropriate H1- and H2-receptor blockers is important to avoid potential complications from laser-induced mediator release. Total electron beam radiation has been successfully used in one patient.4 Psoralen with UVA and UVB, which inhibits the release of histamine by mast cells, has been used for the treatment of mastocytosis. This approach might also work for TMEP, but no studies have been reported.

Workup of this patient, who had few symptoms, revealed  laboratory results that were within normal limits. He was reassured that his skin eruption, while noticeable, did not pose a threat to his overall health.

Dr. Scheinfeld is assistant clinical professor of dermatology at Columbia University in New York City, where he has a private practice.

References

1. Vidal C, del Rio E, Suárez-Peñaranda J, Armisén M. Telangiectasia macularis eruptiva perstans presented as a pseudoallergic food reaction. J Investig Allergol Clin Immunol. 2000;10:248-250.
2. Donahue JG, Lupton JB, Golichowski AM. Cutaneous mastocytosis complicating pregnancy. Obstet Gynecol. 1995;85(5 Pt 2):813-815.
3. Kanthawatana S, Carias K, Arnaout R, et al. The potential clinical utility of serum alpha-protryptase levels. J Allergy Clin Immunol. 1999;103:1092-1099.
4. Monahan TP, Petropolis AA. Treatment of telangiectasia macularis eruptiva perstans with total skin electron beam radiation. Cutis. 2003;71:357-359.