History

Fact Explanation
Rash Tinea nigra is a chronic and asymptomatic dermatomycosis of the stratum corneum of skin caused by Exophiala werneckii or Cladosporium werneckii (also named as Phaeoannellomyces werneckii). Infection occurs by an inoculation from contaminated soil, sewage, wood, or compost. A trauma can innoculate the fungi. This fungi can produce melanin which results in a macule. It is a well-demarcated brown-black macular lesions which usually occur on the palmar aspects of hands and occasionally the plantar and other surfaces of the skin. The lesion is usually single, not itching and painless. [1,2,3,4]
No redness Lesions are usually non-inflammatory. [1]
References
  1. ROSSETTO AL, CRUZ RC. Tinea nigra: successful treatment with topical butenafine. An Bras Dermatol [online] 2012 Nov-Dec, 87(6):939-41 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23197223
  2. ROSSETTO AL, CORRêA PR, CRUZ RC, PEREIRA EF, HADDAD JUNIOR V. A case of Tinea nigra associated to a bite from a European rabbit (Oryctolagus cuniculus, Leporidae): the role of dermoscopy in diagnosis An Bras Dermatol [online] 2014, 89(1):165-166 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142539
  3. GUARENTI ISABELLE MAFFEI, ALMEIDA JR HIRAM LARANGEIRA DE, LEITãO ALINE HATZENBERGER, ROCHA NARA MOREIRA, SILVA RICARDO MARQUES E. Scanning electron microscopy of tinea nigra. An. bras. dermatol. [online] 2014 April, 89(2):334-336 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142780
  4. LARANGEIRA DE ALMEIDA H JR, DALLAZEM RN, DOSSANTOS LS, HALLAL SA. Bilateral tinea nigra in a temperate climate. Dermatol Online J [online] 2007 Jul 13, 13(3):25 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18328219

Examination

Fact Explanation
Macular lesion These are usually well-demarcated brown-black (hyperpigmented) macular lesions.They presents as a solitary lesion, although more than one lesion can be present. The typical location is the palmar or plantar surfaces of the hands or feet. Rarely, some cases has been presented over the neck and chest. The shape may appear ovoid, round, or irregular. [1,2]
No erythema Tinea lesions are non-inflammatory. [1,2]
No scaling Outer layer of the epidermis (Stratum corneum) is not affected by tinea infection. Therefore scaling does not happen. [1]
Dermoscopy findings Darkened irregular puntiform pigmentation is characteristic for tinea nigra. These pigmentation does not follow the furrows and ridges normally observed in the skin. [1,2,3]
References
  1. ROSSETTO AL, CRUZ RC. Tinea nigra: successful treatment with topical butenafine. An Bras Dermatol [online] 2012 Nov-Dec, 87(6):939-41 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23197223
  2. ROSSETTO AL, CORRêA PR, CRUZ RC, PEREIRA EF, HADDAD JUNIOR V. A case of Tinea nigra associated to a bite from a European rabbit (Oryctolagus cuniculus, Leporidae): the role of dermoscopy in diagnosis An Bras Dermatol [online] 2014, 89(1):165-166 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142539
  3. GUARENTI ISABELLE MAFFEI, ALMEIDA JR HIRAM LARANGEIRA DE, LEITãO ALINE HATZENBERGER, ROCHA NARA MOREIRA, SILVA RICARDO MARQUES E. Scanning electron microscopy of tinea nigra. An. bras. dermatol. [online] 2014 April, 89(2):334-336 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142780

Differential Diagnoses

Fact Explanation
Secondary syphilis Secondary syphilis develops several weeks to months after the primary syphilis left untreated. It may manifest as macular, maculopapular, or pustular lesions. The rash may involve all skin surfaces, including the palms and soles. Condyloma latum also is associated commonly in perineum and perianal skin. These lesions are painless but highly infectious. [1,2]
Malignant melanoma Malignant melanoma is a neoplasm of melanocytes or their precursor cells. Usually asymmetrical very dark black or blue irregular lesions which can occur anywhere in the body. There is an associated lymphadenopathy. It may be familial and patient may have a past history of similar lesions. Those who tan easily are also less likely to develop a melanoma. [3]
Melanocytic Nevi Benign hamartomas or neoplasms composed of melanocytes. They may be flat or protruding and vary in colour from pink or flesh tones to dark brown or black. They range in size from millimetres to several centimetres and mostly round or oval in shape. [4]
Post inflammatory hyperpigmentation It implies the discoloration that is left on the skin after the healing of an underlying skin disease such as skin infections, allergic reactions, mechanical injuries, reactions to medications and trauma. These are located at the site of the primary disease. The color ranges from light brown to black and may become darker if exposed to sunlight. [5]
Addison disease Chronic endocrine disorder in which the adrenal glands do not produce sufficient steroid hormones. Generalized hyperpigmentation is most evident on areas exposed to light.It may also appear on the nipples, armpits, genitals and gums. [6,7]
References
  1. USATINE RP. The palms and soles West J Med [online] 2000 Sep, 173(3):160-161. [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071050
  2. BROWN,D.L., J.E. FRANK. Diagnosis and Management of Syphilis, Am Fam Physician[online]. 2003 Jul,15,68(2),283-290. [viewed 18 May 2014] Available from: http://www.aafp.org/afp/2003/0715/p283.html
  3. ROSSETTO ANDRé LUIZ, CRUZ ROSANA Cé BELLA, HADDAD JUNIOR VIDAL. DOUBLE-BLIND STUDY WITH TOPICAL ISOCONAZOLE AND TERBINAFINE FOR THE TREATMENT OF ONE PATIENT WITH BILATERAL Tinea nigra plantaris AND SUGGESTIONS FOR NEW DIFFERENTIAL DIAGNOSIS. Rev. Inst. Med. Trop. Sao Paulo [online] 2013 April, 55(2):125-128 [viewed 18 May 2014] Available from: doi:10.1590/S0036-46652013000200011
  4. ROCHA CR, GRAZZIOTIN TC, REY MC, LUZZATTO L, BONAMIGO RR. Congenital agminated melanocytic nevus--case report. An Bras Dermatol [online] 2013 Nov-Dec, 88(6 Suppl 1):170-2 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20132137
  5. DAVIS EC, CALLENDER VD. Postinflammatory Hyperpigmentation: A Review of the Epidemiology, Clinical Features, and Treatment Options in Skin of Color J Clin Aesthet Dermatol [online] 2010 Jul, 3(7):20-31 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921758
  6. GRANER JL. Addison, pernicious anemia and adrenal insufficiency. CMAJ [online] 1985 Nov 1, 133(9):855-7, 880 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/3902186
  7. ROSS IL, LEVITT NS. Addison's disease symptoms--a cross sectional study in urban South Africa. PLoS One [online] 2013, 8(1):e53526 [viewed 18 May 2014] Available from: doi:10.1371/journal.pone.0053526

Investigations - for Diagnosis

Fact Explanation
Microscopic examination Scrapings taken from the edge of the scaly lesion are microscopically examined after being treated with 20% pottasium hydroxide. It shows mycelium (a group of branched filaments or hyphae). The hyphae are septate, branched and have dark pigmentation in walls. [1,2,3]
Culture Culture grows black colonies of Exophiala werneckii or Cladosporium werneckii on sabouraud agar within a week. The colonies are shiny, humid and black. [1,2,3]
Biopsy Skin biopsy is not essential in diagnosing the disease. Histologically, Tinea nigra shows hyperkeratosis and mild acanthosis. [1]
Dermoscopic examination Darkened irregular puntiform pigmentation is characteristic for tinea nigra. These pigmentation does not follow the furrows and ridges normally observed in the skin. [1,2]
References
  1. ROSSETTO AL, CRUZ RC. Tinea nigra: successful treatment with topical butenafine. An Bras Dermatol [online] 2012 Nov-Dec, 87(6):939-41 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23197223
  2. ROSSETTO AL, CORRêA PR, CRUZ RC, PEREIRA EF, HADDAD JUNIOR V. A case of Tinea nigra associated to a bite from a European rabbit (Oryctolagus cuniculus, Leporidae): the role of dermoscopy in diagnosis An Bras Dermatol [online] 2014, 89(1):165-166 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142539
  3. LARANGEIRA DE ALMEIDA H JR, DALLAZEM RN, DOSSANTOS LS, HALLAL SA. Bilateral tinea nigra in a temperate climate. Dermatol Online J [online] 2007 Jul 13, 13(3):25 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18328219

Management - General Measures

Fact Explanation
Parent education and preventive measures Good hygienic measures such as regular hand washing is a main preventive method. Patient should be educated to avoid sharing things such as clothing with others. Good skin hygiene, good nail hygiene are also important. Prolonged wetting of skin and feet should be avoided. [1]
References
  1. Tinea pedis. Br Med J [online] 1968 Oct 26, 4(5625):204-5 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/5682318

Management - Specific Treatments

Fact Explanation
Topical antifungal agents The creams are applied to the affected area twice daily for two to four weeks, including a margin of several centimetres of normal skin. The treatment is continued for one or two weeks after the last visible rash has cleared. Repeated treatment is often necessary. Ciclopirox olamine is found to be more effective. Isoconazole, terbinafine, butenafine and amorolfine oxiconazole are the other effective topical antifungals. Systemic antifungals are not needed because topical antifungals have been successful. [1,2,3]
References
  1. ROSSETTO AL, CRUZ RC. Tinea nigra: successful treatment with topical butenafine. An Bras Dermatol [online] 2012 Nov-Dec, 87(6):939-41 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23197223
  2. ROSSETTO AL, CORRêA PR, CRUZ RC, PEREIRA EF, HADDAD JUNIOR V. A case of Tinea nigra associated to a bite from a European rabbit (Oryctolagus cuniculus, Leporidae): the role of dermoscopy in diagnosis An Bras Dermatol [online] 2014, 89(1):165-166 [viewed 18 May 2014] Available from: doi:10.1590/abd1806-4841.20142539
  3. LARANGEIRA DE ALMEIDA H JR, DALLAZEM RN, DOSSANTOS LS, HALLAL SA. Bilateral tinea nigra in a temperate climate. Dermatol Online J [online] 2007 Jul 13, 13(3):25 [viewed 18 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/18328219