African histoplasmosis is a fungal infection caused by ''

Histoplasma capsulatum ''Histoplasma capsulatum'' is a species of dimorphic fungus. Its sexual form is called ''Ajellomyces capsulatus''. It can cause pulmonary and disseminated histoplasmosis. ''H. capsulatum'' is "distributed worldwide, except in Antarctica, but m ...

'' var. ''duboisii'', or ''Histoplama duboisii'' (Hcd). Disease has been most often reported in

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

Zaire Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, ...

(Democratic Republic of the Congo) and

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

, as Hcd is exclusive to

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. In human disease it manifests differently than

histoplasmosis Histoplasmosis is a fungal infection caused by '' Histoplasma capsulatum''. Symptoms of this infection vary greatly, but the disease affects primarily the lungs. Occasionally, other organs are affected; called disseminated histoplasmosis, it can ...

(caused by ''

'', or Hcc), most often involving the skin and bones and rarely involving the lungs. Also unlike Hcc, Hcd has been reported to rarely present in those with

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

, likely due to underreporting. However, this along with the differences in Hcc and Hcd have been disputed. The favored locations of African histoplasmosis are "osteoarticular, ganglionic and pulmonary". Genitourinary skin damage is rare, occurring in only 4-11% patients and typically as a secondary skin invasion in those with disseminated infection. It presents as "localized with isolated skin, bone, or lymph node infections or disseminated with multiple cutaneous

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classif ...

s present all over the body, subcutaneous abscesses, enlarged lymph nodes,

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

and

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

, and visceral organ enlargement" Cutaneous manifestations can be isolated or present with nodules,

papule A papule is a small, well-defined bump in the skin. It may have a rounded, pointed or flat top, and may have a dip. It can appear with a stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some h ...

s, or

ulcer An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...

s. They may present with subcutaneous swelling, cold abscesses progressing to spontaneous fistulization, or ulcers that may bud. If left alone, lesions may turn into a large ulcer.

See also

References

Further reading