Tuberculids: A Narrative Review.

Tuberculids are a group of dermatoses with tuberculoid histology and the absence of tubercle bacilli. They are considered to be hypersensitivity reactions to circulating Mycobacterium tuberculosis (M. tb) or its antigens in individuals with good immunity. The objective of the review is to provide a detailed literature review of all available articles on tuberculids in the past 10 years and provide an update on epidemiology, etiopathogenetic mechanisms, clinical manifestations, and treatment. A search was performed on PubMed using the keywords lichen scrofulosorum, papulonecrotic tuberculid, erythema induratum, and erythema nodosum tuberculosis for all articles, with no restrictions on age, gender, or nationalities. An update on tuberculids, including some new concepts in pathogenesis, atypical presentations, new investigative modalities, and treatments are reviewed.

Cutaneous tuberculosis. Part I: Pathogenesis, classification, and clinical features.

Tuberculosis is an ancient disease that continues to affect an estimated 10 million people per year and is responsible for 1.4 million deaths per year. Additionally, the HIV epidemic and multidrug resistance present challenges to disease control. Cutaneous tuberculosis is an uncommon, often indolent, manifestation of mycobacterial infection that has a varied presentation. Its diagnosis is challenging, as lesions mimic other, more common conditions and microbiological confirmation is often not possible. Cutaneous tuberculosis can be broadly categorized into multibacillary and paucibacillary forms. Approximately one-third of skin tuberculosis is associated with systemic involvement. By recognizing cutaneous tuberculosis early, dermatologists can play an important role in disease control. The first article in this 2-part continuing medical education series describes the latest epidemiology, microbiology, and pathogenesis of tuberculosis. Furthermore, we review the classification, clinical manifestations, common clinical differentials, and systemic involvement that occur in cutaneous tuberculosis.

Cutaneous tuberculosis. Part II: Complications, diagnostic workup, histopathologic features, and treatment.

Despite the availability of effective treatment regimens for cutaneous tuberculosis, challenges to disease control result from delayed diagnosis, infection with multidrug-resistant mycobacterial strains, and coinfection with HIV. Delayed diagnosis can be mitigated when dermatologists are sensitized to the clinical signs and symptoms of infection and by the incorporation of appropriate diagnostic tests. All cases of cutaneous tuberculosis should be confirmed with histopathology and culture with or without molecular testing. In each case, a thorough evaluation for systemic involvement is necessary. Mycobacteria may not be isolated from cutaneous tuberculosis lesions and therefore, a trial of antituberculosis treatment may be required to confirm the diagnosis. The second article in this 2-part continuing medical education series describes the sequelae, histopathology, and treatment of tuberculosis.

Papulonecrotic tuberculid caused by Bacille Calmette-Guerin vaccination requiring no antitubercular agents.

This paper describes a case of papulonecrotic tuberculid after Bacille Calmette-Guerin (BCG) vaccination. A 6-month-old boy was seen in our emergency room with a fever and erythematous papular. He received BCG vaccination at the age of 5 months and there were no systemic problems after the vaccination. There were no abnormal physical findings except for skin lesions and fever. Histopathologically, the lesion was associated with pyogenic granulomatous inflammation and fibrosis, with multiple instances of vascularization and infiltration of various inflammatory cells. Acid-fast stain, culture,and polymerase chain reaction for tuberculous bacillus DNA of the papulonecrotic skin lesions were negative. He was diagnosed papulonecrotic tuberculid caused by BCG vaccination. The fever lasted 10 days, and all lesions healed spontaneously in 2 months. Papulonecrotic tuberculid is a vasculitis caused by an allergic reaction to an internal focus of Mycobacterium tuberculosis or its metabolites. The appearance of an unexplained skin rash may cause parental anxiety, nevertheless the disease may require no treatment unless the patient is immunocompromised. It is necessary to improve awareness regarding the disease as a side effect of BCG vaccination.

Perforating Granuloma Annulare Mimicking Papulonecrotic Tuberculid.

Perforating granuloma annulare (PGA), a rare variant of granuloma annulare, is characterized by transepidermal elimination of altered collagen that clinically manifests an umbilicated papule with a central crust. It can be confused with papulonecrotic tuberculid (PNT) because of their similar appearance. Unlike PGA, PNT is usually related to tuberculosis infection with a typical histologic finding of wedge-shaped dermal necrosis. Here, we report the first Korean case of PGA mimicking PNT both clinically and histologically. A 43-year-old Korean woman presented with erythematous papules localized on the extensor surface of her limbs for one year. Some of these papules had a central umbilication or a crust. Regarding comorbidity, she had latent tuberculosis diagnosed with QuantiFERON®-TB Gold test about five months ago. She was on antituberculous medication. Initially, a diagnosis of papulonecrotic tuberculid accompanied by latent tuberculosis was considered. However, despite taking the antituberculous medication for five months, her skin lesions were not improved. Biopsy specimen from her arm lesion showed wedge-shaped area of necrosis in the dermis. Additionally, there were multiple focal mucin depositions and palisading granulomatous inflammation throughout the dermis. A diagnosis of PGA was made and she was treated with topical corticosteroid. After two weeks of applying topical corticosteroid, most of her skin lesions disappeared, leaving some hyperpigmented scars.

Perforating Granuloma Annulare Mimicking Papulonecrotic Tuberculid

Perforating granuloma annulare (PGA), a rare variant of granuloma annulare, is characterized by transepidermal elimination of altered collagen that clinically manifests an umbilicated papule with a central crust. It can be confused with papulonecrotic tuberculid (PNT) because of their similar appearance. Unlike PGA, PNT is usually related to tuberculosis infection with a typical histologic finding of wedge-shaped dermal necrosis. Here, we report the first Korean case of PGA mimicking PNT both clinically and histologically. A 43-year-old Korean woman presented with erythematous papules localized on the extensor surface of her limbs for one year. Some of these papules had a central umbilication or a crust. Regarding comorbidity, she had latent tuberculosis diagnosed with QuantiFERON®-TB Gold test about five months ago. She was on antituberculous medication. Initially, a diagnosis of papulonecrotic tuberculid accompanied by latent tuberculosis was considered. However, despite taking the antituberculous medication for five months, her skin lesions were not improved. Biopsy specimen from her arm lesion showed wedge-shaped area of necrosis in the dermis. Additionally, there were multiple focal mucin depositions and palisading granulomatous inflammation throughout the dermis. A diagnosis of PGA was made and she was treated with topical corticosteroid. After two weeks of applying topical corticosteroid, most of her skin lesions disappeared, leaving some hyperpigmented scars.

Papulonecrotic tuberculid-clinicopathologic and molecular features of 12 Indian patients.

BACKGROUND: Papulonecrotic tuberculid (PNT) is said to be a hypersensitivity reaction to M. tuberculosis. Some reports indicate that organisms are demonstrable by polymerase chain reaction (PCR). METHODS: We describe 12 patients with PNT over 6 years. We reviewed the histopathologic features, clinical data and follow-up. PCR for M. tuberculosis DNA was done in all cases. RESULTS: There were 7 men and 5 women. The ages ranged from 3-58 years. Upper limbs were commonly involved (8 cases). All patients had multiple papulonodular lesions, 5 showed ulceration and scarring. Mantoux test was strongly positive in all. Seven patients had systemic tuberculosis. On microscopy, necrosis was seen in 11 cases, varying from minimal to extensive. Epithelioid granulomas were common, except for 1 case with palisading and interstitial patterns. The infiltrate showed mostly lymphocytes, while 3 cases showed eosinophils. Vasculitis was seen in 8 cases. Two cases had dermal mucin, one also with interface dermatitis. This patient had concurrent LE. Mycobacterial DNA was detectable by PCR in 3 cases. Seven patients showed improvement/resolution of lesions on treatment. CONCLUSIONS: PNT is a rare disease. A positive PCR reiterates the question whether these are "tuberculids". PNT may be better classified as true cutaneous tuberculosis and patients screened for systemic disease.

Papulonecrotic tuberculid in a patient with pulmonary tuberculosis.

A 55-year-old male presented with recurrent crops of crusted papular lesions and boils over buttocks for 1month along with a short history of productive cough. The diagnosis of papulonecrotictuberculid (PNT) with pulmonary tuberculosis was made based on history, clinical features, laboratory investigations, and response to antitubercular treatment.

Papulonecrotic tuberculid of glans penis: A common disease at an uncommon site.

A 65-year-old man presented with multiple asymptomatic papulo-pustules and ulcers over glans penis since last 1 year. The lesions used to resolve spontaneously in a few days with scarring. The clinical features and histopathology were suggestive of papulonecrotic tuberculids of the glans penis.

Papulonecrotic Tuberculid with Positive Acid-fast Bacilli.

Two patients suffered from 'boils' on their arms and/or thighs for several months. A diagnosis of papulonecrotic tuberculid (PNT) was made based on clinical, laboratory parameters, histopathology, and a prompt response to multi-drug anti-tuberculosis treatment. We checked the pathological sections carefully and finally found a small amount of positive acid-fast bacilli. We analyzed the clinical and histopathological features of PNT in order to offer reference of preventing and controlling the disease.

Tubercúlide papulonecrótica: Caso clínico / Papulonecrotic tuberculid: Case report

Una niña de 12 años fue atendida por presentar pápulas milimétricas diseminadas que involucionaron hacia escaras varioliformes. La prueba de tuberculina fue fuertemente reactiva. Se diagnosticó una tuberculosis pulmonar subyacente y la paciente respondió al tratamiento antituberculoso. La tubercúlide papulonecrótica es una erupción cutánea que se cree debida a hipersensibilidad ante un foco subyacente de tuberculosis y sería un indicador de buen estado inmunitario.

A 12-year-old girl was seen with widespread millimetric papules which resolved leaving varioliform scars. Tuberculin test was strongly reactive. Underlying pulmonary tuberculosis was diagnosed. The patient responded to antituberculous treatment. Papulonecrotic tuberculid is a skin eruption thought to be due to hypersensitivity to an underlying focus of tuberculosis and is an indicator of good immunologic status.

Tubercúlide papulonecrótica: Caso clínico / Papulonecrotic tuberculid: Case report

Una niña de 12 años fue atendida por presentar pápulas milimétricas diseminadas que involucionaron hacia escaras varioliformes. La prueba de tuberculina fue fuertemente reactiva. Se diagnosticó una tuberculosis pulmonar subyacente y la paciente respondió al tratamiento antituberculoso. La tubercúlide papulonecrótica es una erupción cutánea que se cree debida a hipersensibilidad ante un foco subyacente de tuberculosis y sería un indicador de buen estado inmunitario.(AU)

A 12-year-old girl was seen with widespread millimetric papules which resolved leaving varioliform scars. Tuberculin test was strongly reactive. Underlying pulmonary tuberculosis was diagnosed. The patient responded to antituberculous treatment. Papulonecrotic tuberculid is a skin eruption thought to be due to hypersensitivity to an underlying focus of tuberculosis and is an indicator of good immunologic status.(AU)

Papulonecrotic tuberculid: report of a clinical case.

Papulonecrotic tuberculid is a rare, chronic, recurrent and symmetric eruption of necrotizing skin papules arising in crops, involving primarily the limbs. It occurs in less than 5% of active tuberculosis. Typically bacilli are not detected in any of the cutaneous lesions. Extracutaneous tuberculosis primary focus is only detected in 30-40% of the cases, being the lymph nodes the most common location. Antituberculosis treatment is rapidly effective and is often the main confirmation of the diagnosis.

A Case of Tuberculous Lymphadenitis accompanying Papulonecrotic Tuberculid / 결핵및호흡기질환

Lymphadenitis is a common manifestation in tuberculous diseases. However, papulonecrotic tuberculid is an uncommon cutaneous manifestation, and is considered an allergic reaction against tuberculous bacilli in tuberculous lesions other than the lymph nodes. A wide great variety of cutaneous manifestations arise over a period of a few weeks - i.e., papules, necrosis, crusted and atrophic scars. We described a 27-year-old woman with right cervical tuberculous lymphadenitis and skin lesions involving her arms, legs and both fingers. Histopathologically, a leukocytoclastic vasculitis with V-shaped epidermal necrosis was observed in the upper and deep dermis, including the good response to anti-tuberculosis therapy support the diagnosis of papulonecrotic tuberculid.

A Case of Papulonecrotic Tuberculid Combined with Erythema Induratum / 대한피부과학회지

We report a rare case in which two tuberculids, erythema induratum and papulonecrotic tuberculid, occured together. A 15-year-old Korean girl had two types of clinically distinct lesions; painful subcutaneous nodules on the legs and pruritic necrotic papules on the trunk and extremity. Mantoux test showed a strong positive reaction. Histopathologic findings of the subcutaneous nodule and necrotic papule were consistent with erythema induratum and papulonecrotic tuberculid, respectively. There was no extracutaneous focus of tuberculosis. Polymerase chain reaction for tuberculosis bacilli in both lesions revealed negative results. Antituberculous therapy brought a rapid clinical improvement of lesions within a month.

A Case of Papulonecrotic Tuberculid Combined with Erythema Nodosum

We report an extremely rare case in which two tuberculids, papulonecrotic tuberculid and erythema nodosum, occurred together. A 16-year-old girl had two types of clinically distinct lesions; asymptomatic necrotic papules on the upper and lower extremities and painful subcutaneous nodules on the legs. A Mantoux test showed a strong positive reaction. Histopathologic findings of the necrotic papule and subcutaneous nodule were consistent with papulonecrotic tuberculid and erythema nodosum, respectively. There was no extracutaneous focus of tuberculosis. Polymerase chain reaction for tuberculous bacilli in the papulonecrotic tuberculid lesion revealed a negative result. Antituberculous therapy brought a rapid clinical improvement of both lesions.