Telangiectasia macularis eruptiva perstans: more than skin deep

Urticaria pigmentosa and systemic mastocytosis

Key Clinical Message

Additional investigations for systemic involvement should be initiated once the diagnosis of cutaneous mastocytosis has been established in an adult patient. A serum tryptase can serve as a screening test for systemic mastocytosis, and persistent elevations should prompt further investigations, such as bone marrow studies.

Abstract

Urticaria pigmentosa (UP) is the most common form of cutaneous mastocytosis, presenting as a wide variety of macroscopic appearances. Cutaneous mastocytosis in pediatric patients usually does not present with systemic involvement, but more than half of adult patients with cutaneous mastocytosis demonstrate systemic involvement. Currently, there is no guidance surrounding systemic testing in patients with UP. A 50-year-old Caucasian male was referred to the Clinical Immunology and Allergy clinic with a history of a rash. He initially presented to hospital 12 years prior with group A beta hemolytic streptococcus bacteremia treated with multiple different antibiotics. One week following discharge, he developed erythematous brown spots on his right leg which were flat, non-pruritic, and not painful. The rash later expanded to his trunk and extremities. A skin biopsy performed 2 years prior to referral to our clinic demonstrated urticaria pigmentosa. The CD117 immunohistochemical stain showed increased perivascular and interstitial mast cells in the superficial dermis. Darier's sign was negative on physical examination, and venom testing was also negative. Although he had no symptoms of systemic involvement, his serum tryptase was elevated at 47.6 ng/mL in the context of normal kidney and liver function. A skeletal survey was normal, and an abdominal ultrasound ruled out splenomegaly. Bone marrow biopsy demonstrated a mild increase in paratrabecular and perivascular atypical mast cells, in keeping with systemic mastocytosis. Adult patients with cutaneous mastocytosis have a high likelihood of having an underlying systemic mast cell disorder. Therefore, any patient presenting with characteristic skin findings should be investigated as having a cutaneous manifestation of systemic mastocytosis. This case demonstrates the utility of serum tryptase and its role in triggering additional investigations and guiding appropriate therapy.

Telangiectasia Macularis Eruptiva Perstans Treated with Narrow-Band UVB Phototherapy and Heliotherapy during the COVID-19 Pandemic

Telangiectasia macularis eruptiva perstans (TMEP) is a rare disease, previously classified as a variant of cutaneous mastocytosis. While no gold standard of treatment exists, several treatments have been studied. We report a case of a 63-year-old woman who presented with long-standing asymptomatic telangiectatic macules beginning on the upper chest, back, and bilateral arms, with occasional pruritus and no other systemic symptoms. Skin biopsy, along with Giemsa stain, revealed findings consistent with TMEP. The patient underwent testing for serum tryptase level, which was within normal limits. The patient was started on topical steroids for two weeks and antihistamine therapy, with a noted decrease in pruritus but no change in cutaneous lesions. She was then advised to start phototherapy, and subsequently underwent a total of five sessions of narrow-band ultraviolet B phototherapy, after which she noted lightening of the lesions. Due to the COVID pandemic, the patient was shifted to heliotherapy with continued lightening of lesions after two months of thrice weekly sessions. This rare case is supportive of narrow-band ultraviolet B phototherapy and heliotherapy as promising treatment options for cases of TMEP.

Telangiectasia Macularis Eruptiva Perstans of the Scalp Mimicking Angiosarcoma

ABSTRACT

We present a case of a 74-year-old man with marked photodamage who was ultimately diagnosed with telangiectasia macularis eruptiva perstans (TMEP) of the scalp. The diagnosis was made more difficult because of the clinical and histological similarity of this case with an early angiosarcoma. TMEP is a benign and indolent rare subtype of cutaneous mastocytosis presenting clinically with red-brown telangiectatic macules, usually symmetrically distributed over the trunk and extremities. Although most cases are limited to the skin, systemic involvement can occur, and this can be a potentially life-threatening disease. Although also rare, in contrast to TMEP, cutaneous angiosarcoma is a highly malignant vascular tumor with a poor prognosis. This case highlights the importance of including TMEP on the differential diagnosis where vascular lesions of the scalp are observed.

Developing a standardized approach for assessing mast cells and eosinophils on tissue biopsies: A Work Group Report of the AAAAI Allergic Skin Diseases Committee

Mast cells and eosinophils are commonly found, expectedly or unexpectedly, in human tissue biopsies. Although the clinical significance of their presence, absence, quantity, and quality continues to be investigated in homeostasis and disease, there are currently gaps in knowledge related to what constitutes quantitatively relevant increases in mast cell and eosinophil number in tissue specimens for several clinical conditions. Diagnostically relevant thresholds of mast cell and eosinophil numbers have been proposed and generally accepted by the medical community for a few conditions, such as systemic mastocytosis and eosinophilic esophagitis. However, for other mast cell- and eosinophil-associated disorders, broad discrepancies remain regarding diagnostic thresholds and how samples are processed, routinely and/or specially stained, and interpreted and/or reported by pathologists. These discrepancies can obfuscate or delay a patient's correct diagnosis. Therefore, a work group was assembled to review the literature and develop a standardized consensus for assessing the presence of mast cells and eosinophils for a spectrum of clinical conditions, including systemic mastocytosis and cutaneous mastocytosis, mast cell activation syndrome, eosinophilic esophagitis, eosinophilic gastritis/enteritis, and hypereosinophilia/hypereosinophilic syndrome. The intent of this work group is to build a consensus among pathology, allergy, dermatology, hematology/oncology, and gastroenterology stakeholders for qualitatively and quantitatively assessing mast cells and eosinophils in skin, gastrointestinal, and bone marrow pathologic specimens for the benefit of clinical practice and patients.

Mechanisms Governing Anaphylaxis: Inflammatory Cells, Mediators, Endothelial Gap Junctions and Beyond

Anaphylaxis is a severe, acute, life-threatening multisystem allergic reaction resulting from the release of a plethora of mediators from mast cells culminating in serious respiratory, cardiovascular and mucocutaneous manifestations that can be fatal. Medications, foods, latex, exercise, hormones (progesterone), and clonal mast cell disorders may be responsible. More recently, novel syndromes such as delayed reactions to red meat and hereditary alpha tryptasemia have been described. Anaphylaxis manifests as sudden onset urticaria, pruritus, flushing, erythema, angioedema (lips, tongue, airways, periphery), myocardial dysfunction (hypovolemia, distributive or mixed shock and arrhythmias), rhinitis, wheezing and stridor. Vomiting, diarrhea, scrotal edema, uterine cramps, vaginal bleeding, urinary incontinence, dizziness, seizures, confusion, and syncope may occur. The traditional (or classical) pathway is mediated via T cells, Th2 cytokines (such as IL-4 and 5), B cell production of IgE and subsequent crosslinking of the high affinity IgE receptor (FcεRI) on mast cells and basophils by IgE-antigen complexes, culminating in mast cell and basophil degranulation. Degranulation results in the release of preformed mediators (histamine, heparin, tryptase, chymase, carboxypeptidase, cathepsin G and tumor necrosis factor alpha (TNF-α), and of de novo synthesized ones such as lipid mediators (cysteinyl leukotrienes), platelet activating factor (PAF), cytokines and growth factors such as vascular endothelial growth factor (VEGF). Of these, histamine, tryptase, cathepsin G, TNF-α, LTC₄, PAF and VEGF can increase vascular permeability. Recent data suggest that mast cell-derived histamine and PAF can activate nitric oxide production from endothelium and set into motion a signaling cascade that leads to dilatation of blood vessels and dysfunction of the endothelial barrier. The latter, characterized by the opening of adherens junctions, leads to increased capillary permeability and fluid extravasation. These changes contribute to airway edema, hypovolemia, and distributive shock, with potentially fatal consequences. In this review, besides mechanisms (endotypes) underlying IgE-mediated anaphylaxis, we also provide a brief overview of IgG-, complement-, contact system-, cytokine- and mast cell-mediated reactions that can result in phenotypes resembling IgE-mediated anaphylaxis. Such classifications can lead the way to precision medicine approaches to the management of this complex disease.

Extensive Cutaneous Mastocytosis After Pregnancy

Mastocytosis is an uncommon disease involving the proliferation of mast cells within at least one organ system, most commonly the skin. One rare variant is telangiectasia macularis eruptive perstans (TMEP). The telangiectatic tan-brown macules are highly characteristic, although a biopsy is indicated to confirm the diagnosis. We present a 33-year-old white woman who presented for a skin check with concern for a four- to six-year history of "moles" present on the majority of body surface area. Her lesions presented shortly after her first pregnancy and spared sun-exposed face, neck, and extremities. Both of these features are rather unusual in TMEP. In this asymptomatic patient, workup focused on excluding systemic manifestations and discussion of cosmetic treatments. Punch biopsies revealed nests of CD117+ mast cells as well as increased basal melanocytes. Because the lesions spared sun-exposed regions, sunbathing was advised for initial treatment.